Actress Kristin Davis is smitten with her biggest role yet: motherhood. The " Sex and the City" star became a mother to daughter Gemma Rose last August and said the seven months have flown by.

"She's a big girl. She just last week started pulling herself up to standing," Davis said today on " Good Morning America." "It really goes by fast. Everyone says that, but until you're there you really can't quite believe it. It's a lot of responsibility being a single mom, but in some ways I wish I had come to it sooner."

Davis, 47 adopted Gemma through a domestic agency, a process she admits she was wary about at first.

"I had seen too many nighttime television shows about the drama [of domestic adoptions]. I was very nervous," she said. "I had planned to do it internationally, but I realized the wait was three to five years and I just couldn't wait that long. Here in our country we have kids in need and the foster system is not really a great option. Once I made the decision, it moved very quickly and I have a beautiful, healthy, baby girl."

Fans fell in love with Davis through the years as Charlotte on "Sex and the City," a role she says she would love to reprise in another movie.

"I would love to do it. I think we would all love to do it," Davis said. "Maybe it will happen. We've really never known what would happen in our journey with 'Sex and the City.' We always think it's over and then it's not. Whenever we see each other we always talk about it socially."

Davis said ideas for a third installment have been floated, but there is no script. " Sex and the City 2" fared relatively well in theaters thanks to the large series fan base, but did not compare to the 2008 film, which dominated at the box office and grossed over $415 million worldwide.

Davis' latest project is a far cry from "SATC." She plays a mother who is struggling to care for her mentally ill sister and her family in the Lifetime movie "Of Two Minds," which she also executive produced.

"I wanted to make ['Of Two Minds'} because it deals with a family who has a member who has schizophrenia …it's just kind of looking at the stigma about mental illness in our country still and how the burden really falls on the family oftentimes to take care of that person. It's so hard to find health care that will help, or maybe people are afraid to admit it," Davis said on "GMA."

"Of Two Minds" will debut on Lifetime Saturday, March 10, at 8 pm ET/PT.