Sharon Stone, a single mom to three children younger than 7, says she's amazed that she can do it all.
Asked what is the most surprising part of being a mom, Stone, 49, told PEOPLE on Saturday: "That I can actually accomplish it all every day. And get them all under blankets every night."
The actress, who is mother to sons Roan, 6, Laird, nearly 2, and 10-month-old Quinn, was co-hosting the first-ever Class of Hope Prom, which raised money to help underprivileged teens buy dresses and tuxedos for their own proms.
"She's a great mama," said Stone's sister Kelly, 46, who co-hosted the event. "I was there the other day when they were going to bed and they were so cute. I said, 'I don't know how you do it.' I always thought that I would want to be the mom, and I just think now, she's such a good mom, and I could never do it."
That's not to say Stone is ready for more kids. "Right now I have two in diapers and three teething," she said. "That's plenty of children right this minute."
Have her kids been up to anything fun these days? "Oh my gosh, it's all fun," she said. "My littlest one is learning to walk. My next one is learning to talk and my oldest is about to start first grade."
At Saturday's prom-themed gala, at the Sportsmen's Lodge in Studio City, Calif., guests including Melanie Griffith, Fergie, Eric Benet and Tom Arnold relived their high school days to raise funds for the Stone sisters' Planet Hope
Stone, dressed in vintage Versace, has come a long way since her own prom: Her gown, she said, was "a really odd shade of coral. And I had a really bad sunlamp sunburn and bad orange-blonde Sun In hair. [My date] had red hair, so we had lots of shades of orange going on all at the same time."
Reporting by SCOTT HUVER