Re: Why can’t I have a baby with my sim?

You should be able to do it.  The requirements are player level 11 and relationship level 3.

There are two different quests you need to complete in order to have a baby.  The quest "Baby Quest" needs to be completed in order to purchase the Bassinet.  Once that is done the quest "Oh, Baby" needs to be completed to have your first baby.

A few people have been stuck and been able to fix the problem by starting a new relationship (any kind of relationship) and getting it to level 3 (you can then have the baby with your level 10 couple.

If that doesn't work for you, you will probably have to submit a bug report.