IF IT’S TRUE that the apple doesn’t fall far from the tree, then in Mama Dearest, the last novel by the late E. Lynn Harris, it stays close to home through three generations. The novel’s central character,Yancey Harrington Braxton, had been a real star once: a Broadway star with fancy clothes, a fancy apartment, and any man she wanted. So she knows what it’s like to make it big but now finds herself acting in a bus-and-truck company production of Dreamgirls, tromping around the country with a bunch of third-rate actors. The one saving grace of this gig is that it gives her a chance to hang out with her best friend, a gay man. But this isn’t enough to compensate for being around a bunch of wannabe actors. This road show is something she’s only enduring while she waits for her second big break.More than anything, Yancey wants to be famous again.