Six months later she was broken, frozen and "unfamiliar in character", some of the people closest to her have testified.
The former Liberal Party staffer alleges she was raped by then-colleague Bruce Lehrmann inside Parliament House in 2019.
Lehrmann is undergoing a criminal trial in the ACT Supreme Court after pleading not guilty to sexual intercourse without consent.
Kelly Higgins told the court her daughter was fulfilling a dream when she moved to Canberra to work for a federal coalition minister.
"Throughout high school she had studied debating, public speaking, she volunteered for the Young Liberals at university," Ms Higgins told the court.
"She was extremely excited."
But about April 2019, Ms Higgins noticed a change in her daughter.
"Brittany became very distant. Brittany became very quiet," she said.
"She'd lost a lot of weight. She got quite thin. She just looked quite broken."
Ms Higgins described her daughter as becoming unfamiliar to her emotionally and in character.
"She was just so frozen in what had happened to her," she said.
Former housemate Alex Humphreys told the court when she first moved to Canberra, "Britt" was keen to get involved in social events.
"She was lovely, she was bubbly, she was just so enthusiastic about landing her dream job," Ms Humphreys said.
She said Ms Higgins was initially keen to make friends in her new city and they would often attend social gatherings together.
But the following year, Ms Higgins stopped participating socially.
Ms Humphreys said the change happened around the time of the 2019 federal election, which was called weeks after Ms Higgins was allegedly raped.
Despite her best efforts to encourage Ms Higgins to get out of the house, Ms Humphreys said her once bubbly housemate kept to herself.
"She stayed in her room a lot and for the last couple of months that she lived with us ... it was really hard to get her out for social outings," Ms Humphreys said.
"She wouldn't come out of her room ... she didn't really engage at all."
Ms Humphreys assumed at the time election and work stress contributed to the change in Ms Higgins, who was working on the campaign of Liberal senator Linda Reynolds.
Former colleague and ex-boyfriend Ben Dillaway was one of the first people Ms Higgins told about the alleged assault.
Any time he tried to talk to her about the night of her alleged rape she "didn't handle it well".
"She was very much what I would say would be a broken person and any time that night or that event was brought up she broke down," he told the court.
"A light had turned off in her. She was a broken, shattered person."
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