“It would be a blessing,” Lopez, the mother of 4-year-old twins, Max and Emme, told PEOPLE about the prospect of having more kids. “Every day … they just bring so much joy and happiness to your life, [and] they just bring you right back down to earth.”

But as the star of the new movie What to Expect When You’re Expecting, who’s been juggling her American Idol duties while preparing for her upcoming tour, also admits: “I’ve got my hands full.”

Besides, being a single mom is never exactly easy.

“There’s the guilt that comes along with it,” Lopez said. “You leave and they go, ‘Don’t go to work, Mommy!’ “

So how has the star – who last year split with husband Marc Anthony – managed to balance it all? By putting her twins first.

“That’s my philosophy. So as long as that’s … working in the right way, then I can dedicate whatever time I need to dedicate to my career,” she said. “You just do the best you can, and say no when you have to say no.”

And, fortunately, she hasn’t had to do it entirely alone.

“I have a lot of great people in my life who help … at work and at home,” she said. “I have a great family – so all together – we do it. It takes a village.”