Jane Brown married Mr Topham Hatt in 1910, and they had two children together; Barbara Jane, born the year after their marriage, in 1911, and Charles Topham, born three years later in 1914. Upon Topham reciveing a Baronetcy in 1948, Jane became Lady Hatt. She lived with her husband in Wellsworth. She became a widow upon her husband's death in 1956.
Lady Hatt occasionally helps her husband with railway business, and the engines sometimes go to extreme lengths to help throw parties for her birthday. She likes the railway, but had a certain dislike for Annie and Clarabel until they were cleaned and repainted. Although her husband runs a railway, she likes a day out on a boat or in their car.
Percy once had the job of taking Lady Hatt to Great Waterton for a surprise; to see the brass band.
The engines are extremely fond of her and like when she visits the railway or rides in one of their coaches. A kind and gentle woman, Lady Hatt usually praises the engines for their good deeds.
In the first season, Lady Hatt's original outfit consisted of a white top with a light blue blouse with matching trousers. Her hair was also short.
In the third season, Lady Hatt was portrayed in a brief cameo wearing a blue button down. However, the rest of her attire is not shown. Her figure also slimmed and remains the appearance from the third season onwards.
In the fifth season, as well as a portrait image cameo in Thomas and the Magic Railroad, her attire consisted of a pink shirt with an indigo sweater with a white pearl necklace. However, in Lady's Hatt's Birthday Party, she was seen wearing a pink evening gown in the ending sequence.
From the seventh season onward, Lady Hatt's current outfit consists of a blue dress combined with a white trim sweater with a pink heart picture, with matching shoes, and matching hat with a pink hatband and matching flower.
In The Green Controller and in a cameo in Topped Off Thomas, Lady Hatt's appearance temporarily changed; her outfit she had on was a light blue two button dress with a beige hat with a black hatband. She has ever since returned to her seventh season onward outfit.
- Season 1 - Thomas' Train (cameo), Toby and the Stout Gentleman (not named; does not speak) and Thomas in Trouble (not named; does not speak)
- Season 3 - A Scarf for Percy (not named; does not speak) and Bulgy (cameo)
- Season 5 - Lady Hatt's Birthday Party and Sir Topham Hatt's Holiday
- Season 7 - The Runaway Elephant, Bulgy Rides Again (cameo), The Grand Opening and Best Dressed Engine (cameo)
- Season 8 - Thomas and the Tuba (does not speak) and Percy and the Magic Carpet (cameo)
- Season 9 - Percy and the Oil Painting (cameo), Thomas and the Birthday Picnic (does not speak), Tuneful Toots (does not speak) and Flour Power (mentioned)
- Season 10 - Thomas and the Jet Plane (cameo), The Green Controller, Topped Off Thomas (cameo) and Which Way Now? (does not speak)
- Season 11 - Thomas Sets Sail (does not speak), Toby's Triumph (cameo), Thomas and the Runaway Car (does not speak), and Duncan Does it All (cameo)
- Season 12 - Rosie's Funfair Special (cameo), Saved You! and Percy and the Bandstand
- Season 13 - Tickled Pink (cameo), Double Trouble (does not speak), Toby's New Whistle, Thomas and the Runaway Kite (mentioned) and The Biggest Present of All (does not speak)
- Season 14 - Charlie and Eddie (does not speak), Pop Goes Thomas (cameo) and Jitters and Japes (cameo)
- Season 15 - Up, Up and Away!, Wonky Whistle (cameo) and Fiery Flynn (does not speak)
- Season 16 - Express Coming Through (cameo), Thomas and the Rubbish Train (does not speak), Thomas and the Sounds of Sodor (cameo), Muddy Matters (cameo) and Happy Birthday Sir! (does not speak)
- Season 17 - Wayward Winston (not named; does not speak) and The Afternoon Tea Express
- Season 19 - Who's Geoffrey? (mentioned), Diesel's Ghostly Christmas (cameo) and Reds vs. Blues (cameo)
- Season 20 - Engine of the Future
- Season 21 - Terence Breaks the Ice and Confused Coaches (cameo)
- Thomas and the Magic Railroad (mentioned; portrait cameo)
- The Great Discovery
- Hero of the Rails (cameo)
- Misty Island Rescue (cameo)
- Day of the Diesels
- King of the Railway (cameo)
- Sodor's Legend of the Lost Treasure (cameo)
- The Great Race (cameo)
- 1990 - Thomas and the Umbrella (not named; mentioned)
- 1994 - Well Caught! (mentioned)
- 1996 - The Play Train!, Lost Property!, The Brown Bear, and A Day at the Beach! (mentioned)
- 1997 - 'Smile, Please!', The Daisy Chain and Bobbing About!
- 1998 - Potty Parrot! (mentioned), The Carnival!, The Easter Cake!, The Red Squirrel! (does not speak), The Train Game, Look Alike (does not speak), Toby and the Stout Gentleman! (not named; does not speak), and The Big Speech!
- 1999 - Summer Fun!
- 2001 - Rolling Around! (does not speak) and Skating Show! (mentioned)
- 2003 - Seaside Search! (does not speak), Cook Controller! (mentioned), Really Fast Food!, Feeding Time (cameo), Bertie's Bumpy Ride! (does not speak) and The Cat Controller! (does not speak)
- 2004 - The Grand Opening, Night Lights (does not speak), Elephants and Engines (cameo), Holiday Hat (does not speak), Bulgy's Back! (cameo), Monster Mistake! (mentioned), A Nice Quiet Day (not named), Ben's Blunder (mentioned) and Travelling Thomas
- 2005 - Model Engines (not named; does not speak) and Working Christmas (does not speak)
- 2006 - Busy Bee
- 2007 - In for Treatment (cameo)
- 2008 - A Spring Clean! (mentioned), Toby's Triumph (cameo), and Percy and the Left Luggage (mentioned; mistaken for Dowager Hatt), Giant Puffer (possible cameo)
- 2009 - King Arthur (mentioned)
- 2010 - Carnival Costume (does not speak)
- 2011 - The Treasure Hunt, Puffer Portrait (does not speak), and Perfect Panto (does not speak)
- 2012 - Double Trouble (does not speak), Sound Around (cameo), Edward the Hero (mentioned; mistaken for Dowager Hatt), Wonky Whistle (cameo), Up, Up and Away! (does not speak), Express Coming Through! (cameo), and Thomas and the Rubbish Train (mentioned)
- 2013 - Happy Birthday, Sir! (cameo), The Fat Controller's Bedtime Story (Issue 660) (mentioned), The Fat Controller's Bedtime Story (Issue 662), and New Year Party
- 2014 - Valentine's Surprise, Happy Birthday, Sir! (mentioned), and The Afternoon Tea Express (cameo)
Lady Hatt also appeared in the magazine stories, Thomas and the Baby, A Friend's Party, A Hole in One, Dressing Up, Feeding Time, Happy Holiday!, Keeping Dry, Lights On, Lost and Found, Puzzles, Scaredy Puffer!, Snap Happy, Sodor's Strong Man, Station Mystery, The Flower Dome, The Hallowe'en Special, The Tiny Engine, and Working Whistles.
- 1985 - Gale Warning
- Teresa Gallagher (UK; thirteenth season onwards - US; seventeenth and twenty-first seasons)
- Jules de Jongh (US; thirteenth season onwards - excluding seventeenth season)
- Fu Suzuki (Japan; fifth and seventh seasons)
- Ikumi Sugiyama (Japan; tenth - thirteenth seasons)
- Sakura Yoshioka (Japan; Day of the Diesels onwards)
- Ewa Serwa (Poland; thirteenth season onwards)
- Benedikte Kruse (Norway; thirteenth - fifteenth seasons, excluding Day of the Diesels)
- Marianne Westby (Norway; Day of the Diesels only)
- Gabriela Guzmán (Latin America; thirteenth season onwards)
- Sabine Hahn (Germany; Audio Books only)
- Margrit Strassburger (Germany; thirteenth season onwards)
- Blanche Ravalec (France and French speaking Canada; tenth season onwards)
- María Sánchez (Spain)
- Susa Saukko (Finland; thirteenth season onwards)
- Olga Kuznetsova (Russia)
- Elain Llwyd (Wales)
- Vina Papadopoulou (Greece)
She plays Genie as TV Parade Host June in Raymanladdin (ThomasTenCents34526's Style)
- She is the female TV Parade Host.
She plays Hera in Raymancules (ThomasTenCents34526's Style)
- She is Hercules' mother.
She plays Uncle Henry in The Wizard of Oz (ThomasTenCents34526's Style)
- She is Dorothy's aunt and Henry's wife.
She plays Penny's adopted mother in The Rescuers (ThomasTenCents34526's Style)
- She is one of Penny's adopted mother.
- According to Lady Hatt's Birthday Party, Lady Hatt's birthday is during the summer.
- Lady Hatt is the only human character to have a namecard.
- In the Magazines, Lady Hatt is commonly referred to as "Lady Topham Hatt". This was what Wooden Railway called her as well. She is occasionally mistaken for Dowager Hatt also.
- Lady Hatt has changed a few times through the series:
- In the third season, Lady Hatt's appearance drastically changed.
- In the seventh season, she had less makeup on.
- From the twelfth season and onwards, she gained red lipstick.
- Her eye colour has also changed several times, they were blue in season one, black in seasons three through nine, blue again in The Green Controller, black again from the rest of season ten until The Great Discovery, and brown from season twelve and onwards.
- ERTL (discontinued)
- Wooden Railway (discontinued)
- Brio (discontinued)
- Trading Cards (discontinued)
- Departing Now (discontinued)