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.
On one Valentine's Day, Lady Hatt was given a pet cat and bunches of roses by her husband, and then was showered with beautiful lights.
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 series, 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 series, Lady Hatt was portrayed 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 series onwards.
In the fifth series, 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 series onward, Lady Hatt's current outfit consists of a blue dress combined with a white trim sweater with a pink heart pin, 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 series onward outfit.
- Teresa Gallagher (UK; thirteenth series onwards - US; seventeenth series onwards)
- Jules de Jongh (US; thirteenth - fifteenth series)
- Fu Suzuki (Japan; fifth and seventh series)
- Ikumi Sugiyama (Japan; tenth - thirteenth series)
- Sakura Yoshioka (Japan; Day of the Diesels onwards)
- Ewa Serwa (Poland; thirteenth series onwards)
- Benedikte Kruse (Norway; thirteenth - fifteenth series, excluding Day of the Diesels)
- Marianne Westby (Norway; Day of the Diesels only)
- Gabriela Guzmán (Latin America; thirteenth series onwards, excluding twenty second series)
- Rocío Garcel (Latin America; twenty second series only)
- Sabine Hahn (Germany; Audio Books only)
- Margrit Strassburger (Germany; thirteenth series onwards)
- Blanche Ravalec (France and French speaking Canada; tenth series onwards)
- María Sánchez (Spain)
- Susa Saukko (Finland; thirteenth series onwards)
- Olga Kuznetsova (Russia)
- Elain Llwyd (Wales)
- Vina Papadopoulou (Greece)
- 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's appearance has changed drastically throughout the series:
- In the third series, Lady Hatt's appearance changed almost entirely as she gained longer hair, lost her irises, start wearing eyeshadow, and donned a blouse.
- In the seventh series, she had less makeup on.
- From the twelfth series onwards, she had red lipstick.
- Her eye colour has also changed several times, they were blue in series one, black in series three through nine, blue again in The Green Controller, black again from the rest of series ten until The Great Discovery, and brown from series twelve and onwards.