It's been several years since Rebecca Walker became estranged from her mother, the Pulitzer Prize-winning author Alice Walker, a rift that shows no signs of repair. But now that Walker has a new book exploring her nine-month odyssey to childbirth, that mother-daughter relationship has been opened up and dissected again, revealing oftentimes painfully squirmy details. The younger Walker, who is biracial and bisexual, has spent a lifetime -- and a career -- sorting through her issues. Her medium of choice: the memoir, which she likens to ripping off her clothes and strolling through a crowded street.

She's got a knack for self-exposure -- and for courting controversy.

"People are going ballistico," Walker, 37, said Tuesday night after appearing at Borders Books in Tysons Corner. "It's stirring up feelings on both sides."

"It" would be her memoir, "Baby Love: Choosing Motherhood After a Lifetime of Ambivalence" and a certain chapter where she describes the difference between her love for her teenage stepson, Solomon -- whom she still parents with her ex, the singer-musician (and D.C. native) Me'shell Ndegéocello -- and her love for her biological son, Tenzin.

In it, she wrote: "It's not the same. I don't care how close you are to your adopted son or beloved stepdaughter, the love you have for your non-biological child isn't the same as the love you have for your own flesh and blood. It's different. . . . It isn't something we're proud of, this preferencing of biological children, but if we ever want to close the gap I do think it's something we need to be honest about. . . .

"Yes, I would do anything for my first son, within reason. But I would do anything at all for my second child, without reason, without a doubt."

Then came a profile earlier this month in the New York Times, in which she sharpened the distinction. While she knows that she would "die for" Tenzin, she said, she's not sure she would do the same for her non-biological child.

Infuriated letters to the editors ensued. As did angry postings on her blog RebeccaWalker.com, such as this one: "I do not want to speak for all the infertile women in the world who cannot birth their own 'natural' children but your comments in the NYTimes about adoptive parents not experiencing the same level of love as biological parents were about the most insensitive I have ever experienced."

Walker says she was caught off guard by the fallout. These are her feelings, she says, her truth -- a "brutal truth," as she later put it -- but hers nonetheless. She says she's not trying to denigrate the many different incarnations of family and deem one type of love as lesser. Not lesser. Different.

"I think it's healthy to talk about different kinds of love," she says after the reading. "You love each of your children differently. We have to be comfortable with thinking that there are different kinds of love. . . . I think my first son feels differently about his biological mom than he does me. And I'm fine with that."

As an activist, she says, she's spent years celebrating family in all its guises; right now, she's working on an anthology that explores that very issue, "Walk This Way: Introducing the New American Family." After all, she once contemplated creating her own less-than-traditional family. In her memoir, she describes how she and her long-term female partner (whom she does not identify by name) approached a male friend about fathering a child for them. That union did not yield a child. But after the couple broke up, Walker met Glen (she doesn't provide his last name), her Buddhism teacher. Today, unmarried, the couple live in Maui with their son, Tenzin.

"I salute her for writing about those mixed feelings," says the writer Erica Jong, who, along with her own writer daughter, Molly Jong-Fast, knows something about airing mixed feelings about family ties in memoir.

"But not everyone feels that way. A lot of people feel very intensely about their adopted children. Whatever your feelings are, you should be able to write about them, even though they're taboo feelings."

Walker wrote critically about her famous mother in her first memoir, "Black, White and Jewish: Autobiography of a Shifting Self," in 2001: "My parents did not hold me close, but encouraged me to go. They did not buffer, protect, watch out for, or look after me. I was mostly left alone to discover the world and my place in it."

Today the two do not speak; Alice Walker has not met her only grandson.

"We are estranged," Rebecca Walker says.

The prospect of parenthood can be harrowing for any Gen X feminist -- so many choices, so little time. Independence vs. the ticktocking clock; the desire to be adventurously autonomous vs. the desire to love and be loved. Factor in a feud with an iconic mother, and for Walker, motherhood was something to be viewed through a haze of ambivalence.

Until she got the call from the doctor's office informing her that her pregnancy was a viable one.

Now, she wants other women contemplating the leap to motherhood to realize this: Fertility is finite.

At the book signing, a woman raises her hand. Like Walker, she is 37. Like Walker, she's been ambivalent about becoming a mother. She's newly married. Can't she just wait a while? Enjoy the honeymoon? Is being a mother worth it?

"What would you tell me?" she asks Walker.

"It's totally worth it. You don't have much time. Get to it."

Pause. "I'm so sorry."

Walker laughs. Ruefully. And the small crowd -- all female save for one lone male -- laughs with her.