Did the bassinet disappear after the child grew up? If not, I would use the move_objects on/off cheat to remove the crib.
The way this is intended to work is that a crib is created when you decide to have a baby. As the child grows up it runs the "pupate" code which is ages up your sim runs through some flowery blossom, and runs a "Create Child" code. Then the crib deletes itself. However, I don't know if during this process it creates a temporary placement for the child to portal too. It may be that the crib is still there but invisible. I would therefore try clicking around with the move_objects cheat on to see if there are any invisible objects.
Be careful not to delete any portals around your lot that serve other functions, such as for visitors, carpools etc.