Lane Carsh of Walnut Creek calls her daughter, Dawn, her biggest blessing. They are close, share the same wit and love of family. However, she is careful not to call Dawn her best friend. They tried that briefly when Dawn was 18, Lane says. They went shopping, dancing, and talked about "everything." It didn't quite work.

"We would get into arguments like sisters," says Lane, 64. "It wasn't a good thing. A mother needs to have a certain amount of respect, but she has to earn it. How can you be the mother and the best friend?"

The relationship between mother and daughter is complicated. In some circles, there is an expectation that despite the parental connection, the two are also the closest of friends, especially these days, as many young women delay marriage and babies into their 30s.

It is that period of prolonged post-adolescence that has allowed some adult daughters to develop deep bonds with their mothers, according to Susan Morris Shaffer, co-author of "Too Close For Comfort: Questioning the Intimacy of Today's New Mother-Daughter Relationship" (Berkley). While closeness can be healthy and rewarding, she says it works only when parental boundaries are firmly in place.

Without those boundaries, the enmeshment is so strong and suffocating that daughters don't get to express their independence and individuality, says Lafayette psychologist Suzanne Dudeck.

"When you have a girl constantly seeking the approval of her mother, it impedes a maturation process that all of us have to go through," Dudeck says. "We want our moms to be there to hear us rather than act like our girlfriend where we're swapping the details of the story."

Shirley Jacks of Danville and Jodina Ehle of Livermore love relaying an example of how they maintained those boundaries. Jacks, 62, and Ehle, 29, have always considered one another a best friend. They are very much alike — down to their truthful nature and positive outlook on life — and have been particularly close since Ehle left for college.

"She would party with me and my roommates," Ehle recalls. "She was a friend to my friends. I got to see her true, fun self. But there was no fuzzy line. She had a balance between nurturing and protecting me. There were always high expectations and clear consequences."

And Ehle knew what they were. When she was 16, she took off for Santa Cruz with her girlfriends without telling her parents. When Jacks found out, she grounded her daughter for a month. Ehle challenged her mother.

"I thought you were my best friend," she said. "Don't kid yourself," Jacks responded. "I'm your mother first."

Mother, mentor, coach