Jean O'Donnell says claims are laughable as former aide tells how Tea Party favourite believed in curing homosexuality

Family members can be tricky for politicians, as the newest Tea Party favourite, Christine O'Donnell, is discovering this week.

For more than a decade O'Donnell has espoused a strong brand of social conservatism, criticising gays and championing what she called traditional family values. Only three years ago, in a TV interview on Fox News, she complained about a gay rights parade in New York, arguing that homosexual groups could get away with much more than anyone else.

"They're getting away with nudity. They're getting away with lasciviousness. They're getting away with perversion," she said. In other interviews, she objected to the use of the term Aids "victims", saying they had brought it upon themselves, and objected to the appointment of a US ambassador because he was gay and might have ties to a paedophile rights group.

A former O'Donnell staffer, Wade Richards – who worked on a small group she founded in 1996, the Saviour's Alliance for Lifting the Truth – has claimed that she espoused cures for homosexuality.

But it has emerged that O'Donnell's sister, Jean, who works in the theatre in Los Angeles, is openly gay.

On her Facebook profile Jean O'Donnell lists her likes as: "The word 'Fuck', Christine O'Donnell for US Senate, the No H8 Campaign [a group supporting gay marriage], the Dalai Lama and the National Centre for Lesbian Rights."

She campaigned for her sister, saying it was a "neat experience" and has denied that her sister is anti-gay. In a reply to friends congratulating her on Christine's victory, Jean wrote: "… thank you for your love, prayers, good humour and support of my sister, no matter what lies were made up about her … oh … PS, have you heard the latest? she's homophobic … gotta laugh."