In an interview with Health magazine, the actress, who gave birth to son Benjamin in November 2010, revealed that she spent her teenage years surrounded by young children and often took babysitting jobs for next to nothing just to be around them.
"I've always wanted to be a mother, ever since I was 11. I was an expert babysitter. I was doing commercials for thousands of dollars, but I'd still babysit for $3 an hour just because I loved it," Preston recalled.
"I'm just in a good place, and am able to really be with my kids. It's pretty amazing having a child at this age."
Preston, who is married to John Travolta, also insisted that she had no doubts about becoming pregnant again after her 16-year-old son Jett died from a seizure in 2009. She told the magazine that she considers children to be a blessing.
"I didn't have any doubts. I love being pregnant. I love the closeness I feel when I'm carrying them. I love feeling them move inside me. My heart breaks for people who aren't able to have kids. But I feel like there's really hope for anyone," she said.
Preston has credited her belief in Scientology with helping her to cope with Jett's death.