If there is one person who is not happy with Britney Spears' pregnancy news, it is husband Kevin Federline's former girlfriend Shar Jackson who feels the couple hardly know each other yet.

"A baby is not a dog. You can't just put it away," Internet portal Femalefirst quoted the "Moesha" actress as saying.

"I know she (Spears) says she's had experience with kids, but let me say this: 'You have not had experience until you have one of your own. I don't know if Britney realises how hard it will be.'"

Jackson, who is the mother of Federline's children Kori and Kaleb, insists the couple should have allowed their marriage to grow before becoming parents.