First, congratulations on your acceptance. Second, going to b-school is a commitment that both you and your partner make. You are smart to consider potential issues that could arise in her case. Indeed, many spouses have a difficult time for the reasons that you hinted at. Yes, schools do a good job supporing the "spouse club" and a number of spouses get heavily involved in that. Many, however think it's basically a nursery school on steriods (something to keep the spouse occupied and pass the time).
I'm personally of the opinion that it is an excellent time for materinity for many (if you are so inclined). A large number of my classmates decided to have a child during b-school. Any time you decide to have a child, it will require a great deal of engagement. With that said, you would actually have the ability to see your pregnant wife and eventually your child. And healthcare is decent -- certainly nothing to be concerned about. You will probably not be able to be involved in as many activities, but that goes without saying any time you make a decision to get pregnant.
Bottom line, is many of my classmates did it without many problems - in fact it was big joke we had and definitely an option you should consider.