The singer-and-actress - who has two-year-old son, David Jr, with fiance David Otunga - explained while she is desperate for a little girl, she is planning to wait before trying for another child.
She said: "I want a little girl so bad. And my son walks around saying, `I want a sister.
"I want a little girl so bad! But not right now. Give it about three more years."
Despite her desire for a daughter, Jennifer admits David is the "sweetest thing" and has picked up both of his parents` trades, but prefers to switch them around.
She added in an interview with `Access Hollywood`: "He`s always been such a good baby and he`s just the sweetest thing. He`s such a blessing. He`s very advanced for his age, so he likes to talk a lot. He`s a chatterbox.
"He loves to sing, he loves to wrestle. But he likes to wrestle mommy and sing to daddy!"
The Oscar-winning actress recently advised her `Dreamgirls` co-star Beyonce Knowles to get as much sleep as she can while she gets used to being a new mother to week-old baby daughter Blue Ivy.
Jennifer said: "Girl, get your sleep! We talked about this when I had my munchkin. It goes so fast. She`s going to look up and Blue is going to be six months. Next thing you know, she`s going to be walking."