05/21/2007 AT 06:30 PM EDT
Mira Sorvino says she's grappling with her toughest role ever – trying to juggle motherhood with acting.
"I hate it," Sorvino, 39, told PEOPLE at an event in Santa Monica to promote shelter adoptions of dogs and cats. "I feel so guilty because my kids cry so hard when I go to work. I know there are millions and millions of working women out in the world who face this same dilemma, but it just kind of kills me, and I don't know what to do about it."
The Oscar winner for Mighty Aphrodite
and her actor-husband Christopher Backus are the parents of two young children
– Mattea Angel, 2, and 11-month-old Johnny.
On the set of one of a recent movie shoot, Sorvino outfitted the inside of her trailer with kid-friendly decor.
"I've tried to make it as much fun for them as possible on the set," Sorvino said. "I went to FAO Schwarz and got all these things to make the trailer as fun and club-housey as possible. I made a tent with fabric, bought a beanbag chair and put together an art table where my daughter could paint. But days on the set are a minimum of 12 hours and that's hard for them."
"I'd love it," Sorvino laughed, "if I was independently wealthy and could stop acting and just focus on being a mom and activism
Sorvino, who owns three dogs, appeared in Santa Monica on Friday to bring attention to a campaign by pet food manufacturer Hills Science Diet. This year the company is hoping to convince pet lovers to adopt 1 million dogs and cats from animal shelters.