"I wasn't sure I was going to make this public," says Shields, whose daughter Rowan is 2. But, she said, "I'm thrilled for my daughter to have a little friend. Two Tauruses, it's this huge trick being played on me."
Shields, 40, who announced her pregnancy in October, suffered from postpartum depression after the birth of her first child. The actress wrote a book on the subject, Down Came the Rain: My Journey Through Postpartum Depression, and has spoken out about her use of antidepressants – prompting an outcry from Scientologist Tom Cruise, who opposes psychiatry and prescription medication to battle depression.
As for Rowan, Shields tells PEOPLE: "Most 2-year-olds say no before they open their eyes in the morning. Rowan says no and then has reasons why it's no. She digs her heels in, it's amazing how stubborn (she is)."