We have friends that have an 18-month old son.
She still breast feeds him (my wife says that as soon as the little one grows teeth, he's off the boob), they still co-sleep, when they have sex, the baby is still on the bed (that would creep me the hell out), and she won't let the kid out of her sight. She even often has reservations about leaving her son with her dad (who is one of the nicest guys you would ever want to meet) while she goes to the grocery store.
No babysitter is good enough to watch her kid. Her mother in law (who raised two kids might I add) was holding her grandson in the living room and he started crying. She starts to console him, then mom comes over, snatches the kid and walks away without saying a word.
She's become so absorbed that I think that kid is going to grow up to be the biggest pussy ever.