From PEOPLE Magazine Click to enlarge
Six months after Mariska Hargitay and her husband, Peter Hermann, adopted their daughter Amaya, everybody was just getting into the swing of things. "We were just figuring out what she likes and what she doesn't like," Hargitay says. A nursery was up and running on the set of Mom's hit show Law & Order: Special Victims Unit. And, given their lengthy wait before the adoption of Amaya had come through, the couple had already started the process once more so that Amaya and her older brother August, 5, would get a baby brother or sister in the next few years. "We knew we wanted to have more children," Hargitay says. "We thought, 'We should start planning now, since it will take a while.'"

Or not. Just days after their paperwork was processed, Hargitay, 47, got the surprise of a lifetime when she learned that their application had been chosen already and they'd be getting a baby boy, born this summer, that same week. "We never in a million years thought it would happen this quickly, but something inside of us knew that this was right, and we said yes, yes, yes! We knew this was our guy," Hargitay says. When she brought Andrew Nicolas Hargitay Hermann back to their New York City home later that week, "everything about it felt right. It felt divinely right."

Hargitay is the first to admit that the speed and ease of the adoption, which for many people can take years, has been nothing short of miraculous. "We really went through a journey with Amaya," Hargitay says, recalling the emotional yearlong process that resulted in her adoption this spring. Having been through the process so recently, Hargitay, whose celebrity status was not revealed in the initial paperwork, was already fully vetted by their agency and expected things to go more smoothly. What she didn't expect was to get selected just days later. "We're pinching ourselves," she admits. "We're just taking in this blessing."

That's not to say that it hasn't been challenging. "My life feels new, and I sort of don't recognize it," says Hargitay, who has help at home and at her nursery on-set. Everyday tasks have become a major production with two infants. "Getting ready to leave the house was never our strong suit, so now we're severely challenged in that regard," she says with a laugh. "Things like bath time and feeding everybody take so much organization."

While her house was stocked with plenty of diapers and formula, "I had just given away all of August's baby clothes, and I had no time to go shopping," she says. "We came home with our baby and almost nothing." Hargitay quickly converted her home office into a burgundy-and-gold nursery for her son. Friends brought over spare onesies, and big sister Amaya donated some of her items as well. Jokes Hargitay: "When Andrew looks back at pictures, he'll be asking me, 'Mom, why was I in a pink blanket?'"

Getting set up may have taken some work, but settling in as a family has been an easier endeavor. Andrew, who was born prematurely, has a particularly close bond with Amaya, who is just three months older than him. "They'll lie in the crib together, and she'll hold his hand and put her arm around him," says Hargitay. "She's already so protective of him." And August "is over the moon" to have a baby brother and is already asking for more siblings. "Somebody said, 'How did you get your baby brother?' and he said, 'I just asked.' He thinks all he has to do is ask and I'll make it happen."

But showing off photos of her children one Sunday afternoon, Hargitay says she has the feeling their family is finally whole. "There's so much adjusting, but we feel oddly settled now," says Hargitay, adding that she doesn't plan to pursue any more adoptions. "It feels like everyone is home. Our family is complete now. This is what we had in store for us."

With three kids and a full work schedule (Hargitay says she's "very excited" to be shooting SVU's 13th season four days a week; Hermann, 44, is currently starring in a production of War Horse in N.Y.C.), "we're still trying to get synchronized," she admits. "It's mayhem. But the mayhem brings us so much joy."