Ainsley Barton is the daughter and only child of Thad Barton, the patient in the Season 8 episode Risky Business. She was portrayed by actress Alexie Gilmore.
Ainsley arrives at her father's home to find him cleaning up his vandalized property. They have a disagreement both about her father's wish to move the company's production facilities to China and his refusal to contact the police over the vandalism. However, when her father starts having vision problems, she takes him to the hospital.
She is in the room when Gregory House threatens to leak a rumor that Thad is suffering from a mental illness, but she doesn't understand what's going on because House speaks to Thad in Mandarin, which Thad understands but Ainsley doesn't.
When Thad loses consciousness, she realizes she is now in charge of the company. Jessica Adams suggests that she go against her father's wishes, but Ainsley tells her that as long as her father is alive, she will agree to his wishes.
However, House finally treats Thad and he regains consciousness. He asks Thad to issue a press release announcing the company is moving to China, which will boost the company's stock and make House's bet on the stock pay off. Ainsley tries to talk Thad out of it, but Thad signs the release and goes ahead with his plans. This causes the beginning of an estrangement between the two.