The wife of the Vice President of the United States has made a rare public comment about her lesbian daughter.

Lynne Cheney was asked about gay marriage during an interview on CBS television to promote her new book We the People: The Story of the Constitution.

Presenter Harry Smith mentioned the recent wedding of Star Trek actor George Takei in California, where same-sex couples can now marry after a state Supreme Court ruling.

He asked the Second Lady if she would want the same for her daughter Mary.

“I would wish my daughter to have happiness and freedom to make her own choices,” she said.

“The Vice President said in the debate with Joe Lieberman ever so long ago in 2000 that freedom in this country ought to mean freedom for everyone.”

Mrs Cheney has only spoken about her daughter’s sexuality publicly a handful of times.

In 2000, she lambasted a reporter who mentioned it, saying “My daughter has never declared such a thing,” and four years later she attacked Senator John Kerry after he mentioned Mary’s sexuality in a Presidential debate, branding him as “not a good man.

“Of course, I am speaking as a mom, and a pretty indignant mom. What a cheap and tawdry political trick.”

Last year, while promoting another book, this one about life in America during her childhood, she told CBS:

“They were hard on kids who were gay.

“Society has evolved. I’ve evolved in my way of thinking, but I think the whole society has evolved. You know, my mother had a rule which was people are just people.”

During an interview for FOX News yesterday, Mrs Cheney said that Sarah Palin, the Republican candidate for Vice President in November’s election, is being treated unfairly because she is a woman.

“Has anyone asked Senator Obama if he perhaps is neglecting his children by spending too much time on the campaign trail?” she said.

“That’s the kind of question that’s put to Sarah Palin. And I think that’s not fair.”

Mrs Cheney is clearly a fan of the woman who aims to replace her husband as Vice President.

“I was completely surprised and just blown away by her convention speech,” she said.

“You see a lot of slick politicians. I’ve been around politics a long time. I’ve seen people who are really polished and careful and good. She was just excellent and kept that authenticity.”

Vice President Dick Cheney has clashed with journalists over his daughter’s sexuality and her choice to have a baby with her partner, Heather Poe.

Interviewed on CNN’s Situation Room in January 2007, he was congratulated on Mary’s pregnancy by presenter Wolf Blitzer, who then went on to read out a statement from pressure group Focus on the Family.

“Mary Cheney’s pregnancy raises the question of what’s best for children.

“Just because it’s possible to conceive a child outside of the relationship of a married mother and father, doesn’t mean it’s best for the child.”

Mr Cheney, 66, was visibly displeased at the attempt to paint his child as a bad role model.

He replied, “I’m delighted. I’m delighted I’m about to have a sixth grandchild, Wolf, and obviously think the world of both of my daughters and all of my grandchildren.”

Then he added “And I think, frankly, you’re out of line with that question.”

The presenter hastily attempted to mollify Mr Cheney, saying he felt the question was responsible and fair.

“I just fundamentally disagree with your perspective,” the Vice President replied.

Mr Cheney has publicly stated that he did not think there was a need for federal intervention to ban same-sex marriages, and has often spoken publicly of his love, admiration and respect for his daughter.

Ms Cheney’s partner Heather often appears with the Vice Presidential family at official and political functions and events.