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In the December issue of Vanity Fair, Cher opens up about her son, Chaz.

The daughter of Cher and Sonny Bono, Chaz, 41, began undergoing a female-to-male sex change last year. At the time, Cher said, "Chaz is embarking on a difficult journey, but one that I will support."

She is more candid during her Vanity Fair interview, telling editor Krista Smith: "If I woke up tomorrow in a guy's body, I would just kick and scream and cry and f------ rob a bank, because I cannot see myself as anything but who I am -- a girl. I would not take it as well as Chaz has. I couldn't imagine it."

She says she is still getting used to the transition.

"She's a very smart girl--boy! This is where I get into trouble," she says. "I still don't remember to call her 'him.'"

Looking back, it wasn't easy being a parent and being in the spotlight. Her kids are still working through past issues, she says.

"I think Chaz is pretty much finished with it, and I think Elijah [her son, 34, with rocker Gregg Allman] has a little longer to go, but they both really love me a lot," she says. "But it's hard.

"One time, when Chaz was little, we were on a field trip, and she said, 'I’m so pissed off, Mom. You can never not be Cher — we can never just do something.'

"So your kids pay," she continues. "I did the best I could do, and yet it was definitely lacking."

As for aging, Cher - who returns to the big screen at age 64 in this month's Burlesque -- says, "I think Meryl [Streep] is doing it great. The stupid b---- is doing it better than all of us! But I don’t like it. It’s getting in my way. I have a job to do, and it’s making my job harder. "I've been screaming at the top of my lungs at my family, ‘Work out! Work out! Old age is coming!'" she continues. "At some point you will need the strength. Who would have ever thought you would get this old?"

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