"I'm not a young girl anymore who can throw caution to the wind," she told People magazine.
Lopez said live-in boyfriend Smart -- whom she calls by his given name, Beau -- makes her very happy, but following her divorce from musician Marc Anthony, she doesn't want to move too quickly.
"I'm making decisions for three. ... I'm Mama Bear," Lopez said, referring to her life as a single mom with 4-year-old twins Emme and Max. "I want to make sure everything's right. I have been hasty in the past. Super hasty."
The actress said she has no regrets about walking away from a multimillion-dollar gig judging "American Idol" to focus on her acting career, People reported Friday.
She plays a woman picking up the pieces after a divorce in her latest film, "Parker," which co-stars Jason Statham.
"Jennifer walked away from a lot of money on 'American Idol,'" said director Taylor Hackford. "She said, 'You know what? This [acting] is what I want to do right now.'"
"At this point in my life, I lived enough to do great work," Lopez said. "I've really felt everything by now."