Henrietta worked with Toby on their old tramway in East Anglia. She became depressed when buses and lorries took over her work and when their line closed, due to the lack of passengers and freight, Toby could not bear to leave her behind. So Toby brought her with him to the North Western Railway. He mentioned to the Fat Controller that a stationmaster on his tramway wanted to use her as a hen house, but the Fat Controller agreed that "that would never do."
At first, Toby and Henrietta were teased by James for having shabby paint. However, Toby and Henrietta later received new coats of paint for their hard work and James stopped teasing them after he crashed into some tar wagons and spoiled his own paint. When Daisy was brought to Sodor, she insulted Annie, Clarabel and Henrietta when she found that she had to share a shed with them. Percy and Toby were forced to take them away and stay up half the night trying to soothe their hurt feelings. Later, she was used as the Fat Controller's private coach when the engines took a big trip to the Other Railway.
Henrietta is often used to carry quarry workers to and from Anopha Quarry. Once, some workers had to crowd on Henrietta's balcony. However this caused controversy with a Policeman, who sent an inspector to inform the quarry manager of a by-law forbidding passengers to be carried on coaches' balconies. This problem was resolved when the Fat Controller restored an old coach named Victoria to help Toby and Henrietta. Together they formed "Toby's Vintage Train".
One Christmas, villagers from Ulfstead loaded her up with paint pots and presents to give to the engines as a token of gratitude for their hard work in the snow. During a snowstorm, Henrietta allowed Farmer McColl's sheep and newly-born lambs to warm up inside her cabin until the snow thawed. Sometime afterwards, Toby and Henrietta attended the Great Waterton tram parade, alongside Flora and her tram coach.
In the eighteenth season, Henrietta helped Toby get over his fear of Knapford junction. Thomas was sent to pull her (unseen) when Samson accidentally took the express coaches by mistake, because Gordon had to take Thomas' coaches, Annie and Clarabel.
In the nineteenth season, she advised Toby to go to the Steamworks to fix his wobbly sideplates and also told him to fill up with coal on his way to the scrapyard, which he did not. She later heard Paxton talking to Emily about Toby being scrapped and knew that it was nonsense. Emily took Henrietta to the scrapyard where they found Toby safe, but out of coal.
In the twenty-first season, after Toby took her to the Steamworks to getting her seats refurbished, Toby was given a replacement carriage named Hannah. After she had finished her new seats fitted, Toby took Hannah to the Steamworks to be mended, where she reunited with Hannah and revealed to Toby that they were sisters. Afterwards, she began working with Toby once again.
Henrietta is Toby's faithful coach, who likes to be full of passengers and take them on journeys. She does not like to be separated from Toby, although she rarely carries a full load of passengers. Henrietta is quite content with her life on the Island. Toby is attached to Henrietta and always takes her with him, as he says "she might be useful one day".
From the eighteenth season onwards, Henrietta is seen motivating and encouraging Toby when he feels nervous about the capabilities of his work and performance. She also encourages others and gives them good advice.
Henrietta is based on the GER Wisbech and Upwell Tramway 4-wheel coach. From the beginning, the Wisbech & Upwell used its own special passenger stock. Initially, only four wheelers were used, but bogie coaches were introduced in 1884. The coaches had balconies at each end and a drawbridge type gangway between coaches. Each balcony had an emergency hand-brake wheel. The coaches looked squat and low-lying due to the need to handle raised track and the absence of platforms at some of the depots. All the four-wheeled coaches were scrapped by 1948, but the bogie coaches survived into BR. One of them, No.7, has been preserved by the Midland & Great Northern Joint Railway Society.
Hannah is also based on this rolling stock.
In the Railway Series, Henrietta is painted brown with red bufferbeams and a grey roof. During her days with Toby on his old tramway, she was painted brown-orange with red bufferbeams and a white roof.
In the television series, Henrietta is painted brown-orange with red bufferbeams and a grey roof.
- Maggie Ollerenshaw (UK/US; eighteenth season onwards)
- Yumi Nakatani (Japan; first season only)
- Keiko Nemoto (Japan; eighteenth season onwards)
- Marta Dylewska (Poland; eighteenth season onwards)
- Talya Barkay (Israel)
- Isabel Romo (Latin America; eighteenth season onwards, excluding Thomas the Quarry Engine)
- Adriana Casas (Latin America; Thomas the Quarry Engine only)
- Layra Campos (Brazil; eighteenth season onwards)
- Laurence Sacquet (France and French speaking Canada)
- Margret Homeyer (Germany; Audio Book 4 only)
- Sabine Hahn (Germany; Audio Book 10 onwards)
- Vina Papadopoulou (Greece)
- Despite not having a visible face until Thomas and Victoria (in the Railway Series) and the eighteenth season (in the television series), she had the ability to talk in the Railway Series books that took place before Thomas and Victoria, as well as the first and second seasons.
- One of Henrietta's models is currently on display in Japan at the Hara Model Railway Museum (previously on display at Nitrogen Studios).
- In an annual story, it was revealed that Henrietta has one surviving sister left, being a bogie version of herself.
- Throughout the model series, Henrietta's buffers were at different levels at either end.
- Henrietta went through several aesthetic changes in the television series:
- Season 6:
- Her running plate, which was only on her balconies, now runs from end to end.
- Her windows protruded out and the wooden ledge under the window disappeared.
- Her buffer beams slightly changed shape.
- Hero of the Rails:
- She increased in size to be the same height as Toby.
- The area under the side windows change from curving inwards to square and straight.
- Her step ladders slightly changed shape.
- Season 18:
- She gained a face at her back end. To accommodate this:
- Her door disappeared, she lost two of her four windows, and the remaining ones changed shape.
- The two vertical handrails disappeared.
- She gained square pillars on her corners.
- She gained a face at her back end. To accommodate this:
- Henrietta is one of three characters to have been given a face after a certain amount of seasons being without one, the other two being Big Mickey and Butch.
- Season 6:
- ERTL (discontinued)
- Wooden Railway (discontinued)
- Interactive Learning Railway (discontinued)
- Motor Road and Rail (with Toby; discontinued outside Asia)
- TrackMaster (discontinued)
- Collectible Railway (coming soon)
- My First Thomas (discontinued)
- Trading Cards (discontinued)
- Thomas Engine Collection Series (discontinued)
- Mini Die Cast Collection (discontinued)
- Departing Now (discontinued)
- Thomas Town (discontinued)
- Pocket Fantasy (discontinued)
- Departing Now
- Capsule Plarail