It used to be that a parent's worst fear was that a daughter would become pregnant in an untimely fashion or that a child would bring home a fiance who was of a different race or religion. In more enlightened times, the fears had to do with children getting hooked on chemicals. But the new ultimate fear is that your child will turn into a writer and spill the family beans in an autobiography.

The commercialization of sordid family history began with Christina Crawford, who pulled out all the stops in "Mommy Dearest," revealing that an alcoholic Joan Crawford viciously abused her adopted children. Next came B.D. Hyman's book, "My Mother's Keeper," which was about her mother Bette Davis. Hyman said it was an "open letter" to her mother, but it was more of an open letter about her mother, who had a lot in common with Crawford when it came to raising children.

Now comes Patti Davis, daughter of you-know-who, who has written with novelist Maureen Strange Foster a novel called "Home Front." "Patti Davis," reads the book jacket, "the actress daughter of Ronald and Nancy Reagan, has written a surprising, moving and candidly autobiographical novel about growing up in the public eye during the other Vietnam War -- the war at home." Our heroine is a young woman named Beth Canfield, whose father becomes governor of California and calls out the National Guard to halt campus antiwar protests, which he is convinced are the work of Communist agitators, while his daughter turns into a highly visible antiwar activist. When her father sets his sights on the presidency, the daughter's family loyalty is severely questioned by both father and mother, and family ties are seriously strained.

Davis, however, has put a whole new spin on the business of children dragging their famous parents into their literary efforts. She has refused to tell what portions of the novel really did happen and what is pure fiction. Thus, the reader doesn't know what conversations and activities really took place and what didn't.

By Page 2 of the prologue we have the First Family in the White House the night after the inauguration.

"My mother was carrying on conversations as she ducked in and out of rooms, inspecting furniture, drapes, walls.

"There's so much history here! Imagine all the people who have been within these walls. But, good grief, I just can't wait to redecorate."

Ho, ho. We all know where that came from, don't we.

As Beth gets more involved with the antiwar movement, her mother tries to get her disengaged in order to protect her husband's political career. " 'You have no idea how much you hurt your father when you participate in these . . . demonstrations.' She was clutching the handle of her purse so tightly that her knuckles were bluish-white. 'I've tried to give your father a good home life, and you and Brian [Beth's brother], too. Families should stick together,' she continued, 'but you just insist on ruining it. We were so happy when you were born. You were such a lovely little girl . . . . What went wrong?' "

If the reader has trouble sorting out what really happened from what happened in Patti Davis' imagination, consider the plight of her parents. At one point, our heroine reveals that she fell completely in love for the first time in the hayloft at an expensive and toney prep school. Imagine the conversation in the White House when the First Parents read that chapter!

Letting children loose at the computer for autobiographical novels is fraught with dangers. I can see the prose now: "All through dinner, while I was trying to tell mother I was dropping out of college, she was on the phone with a source." Did I or didn't I? Only the author knows for sure.

Which is the case with Patti Davis' book. What does come across in her story, however, are the strains between parents who supported the war, who had given themselves to public service, and children who protested the war and, in those days, jeopardized parents' careers and the welfare of families. At a point of near total alienation from her parents, our heroine writes: "But it was becoming apparent that no matter how far I went, threads of the family fabric still pulled at me. Maybe there were enough left for mending."

It's a story that happened in many families, and "Home Front" may seem a little too close to home for the First Parents. But it says a good deal about them -- and their family -- that their daughter did her mending, not with darts, but with affection and a thoughtful understanding of the elemental beliefs that wrenched the generations apart.