Eva Longoria Calls Her Sister 'My Hero'

11/20/2007 at 04:50 PM EST

Eva Longoria says she's a naturally cheerful person, but her sense of optimism comes directly from her family.

"I've learned there's no better medicine than laughing," says the Desperate Housewives star, who opens up about her family to Parade magazine.

"(My sister) Liza is mentally challenged. She was my hero growing up," she says. "It was a blessing to watch her overcome every obstacle – tying her shoes, putting on a shirt, getting out the front door. And yet she still had a job and would come home on the bus by herself and help with dinner. You could only imagine the hurdles she encountered every minute of the day."

In fact she says her sister helped her career in some ways. "Liza was a role model to get me ready for life in Hollywood," says Longoria. "You don't take health for granted. You don't take life for granted. It seems so insignificant to go, 'Darn it, I didn't get that movie role,' or, 'Darn it, so-and-so is wearing the same dress as me to the Emmys.' "

And having a supportive mother also helped Longoria learn to follow her heart. "My mother is the most non-judgmental person in the world. When I said, 'I'm going to L.A. to be an actress,' she told me, 'All right. I hope that makes you happy.' "

Longoria say's she's as happy as she's ever been. "I love my husband with all my heart," she says of Tony Parker. "I love my family. And I love my girlfriends. And I live my job. And I love my dogs. I love life, in general."