The 38-year-old actress, who has a 10-month-old daughter, Olive, with her husband Will Kopelman, is eager to expand their family in the near future as she doesn't want her little girl to be lonely.
The 'Family Guy' star told the September issue of InStyle magazine: "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 like Rusty and Audrey Griswold from ['National Lampoon's] Vacation'. So however that's going to come about, it's gonna happen!"
Despite wanting more children, Drew is anxious about her skills as a mother as she desperately wants her daughter to have a happy childhood.
She said: "(It's) a lot of pain and a lot of nervousness.
"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. And silly and free, also consistent and grounding."
She added: "Then I just have the same typical fear every other parent has: Are they going to fall down?"