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 coat of paints 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 informed the quarry manager of a by-law forbidding passengers to be carried on coaches' balconies. This problem was resolved when Sir Topham Hatt restored an old coach named, Victoria, to help Toby and Henrietta. Together they formed "Toby's Vintage Train".
Villagers once loaded her up with paint pots and presents to give to the engines as token of gratitude for their hard work in the snow. During a snowstorm, Henrietta allowed Farmer McColl's sheep and newly-born lambs warm inside her cabin until the snow thawed. Sometime afterwards, Toby and Henrietta attended the Great Waterton tram parade, alongside Flora and her tram car.
Henrietta helped Toby get over his fear of Knapford junction.