After spending several weeks in rehab, Eva Mendes says she's "taking a break and having a good time" by exercising and being with her family.

"The sun's out again. It's my time," she told PEOPLE on Tuesday at a luncheon co-hosted by Fresh Cosmetics and the new clothing line Rose at the Hollywood Roosevelt Hotel.

At the event, Mendes, 34, squeezed into a Rose-designed dress – which she described as "chic" and "a little edgy" – with the help of adhesive tape, joking, "I didn't want to take too much of a chance" on a wardrobe malfunction.

To maintain her sexy shape, she says, she's "sticking to my exercise regime," working out four days a week with trainer Harley Pasternak, doing cardio and light weights.

"I'm actually taking advantage of my time off," she says. "You know, I had a film that was pushed, so I'm home spending time with my family, going to the gym and actually enjoying taking care of myself .... This year has been great for me because I've learned how to relax. The last three years have been amazing but kind of crazy. So I don't know, I feel grounded. I feel really good."

"I'm getting a lot of love in the love department, too," adds Mendes, who is in a longtime relationship with producer George Gargurevich.

Earlier this year, the actress entered Utah's Cirque Lodge – the same facility where Lindsay Lohan sought treatment – for what her rep called "outside professional support" for "some personal issues."