The '50 First Dates' star wants to give her 12-month-old daughter Olive a brother or sister because she knows what it is like to feel "lonely" growing up as an only child.
Speaking to the new issue of InStyle UK, she said: "I was an only child and it was lonely. Some people love it and thrive on the independence but I want my kids to have other kids around. Maybe two kids so they can run around life together, roll their eyes at their parents together. So however that's going to come about, it's gonna happen!"
The 38-year-old star and husband Will Kopelman welcomed little Olive in September 2012 and Drew admits she does have some anxiety about being a good parent.
The actress - who tied the knot in June 2012 - explained: "I love the person who said, 'Parenting is like wearing your heart on the outside of your body.' It's the most beautiful, perfect analogy. I have anxieties about how much I'd like to get it right, making sure I provide her with an environment that's safe, nurturing and loving, silly and free, also consistent and grounding.
"Then I just have the same typical fear every other parent has - are they going to fall down?"