I've been working overnights in retail for a couple of years now. I used to work 4 shifts/week, then switched to 4 mornings a week in the cash office and 2 overnight shifts/week. I'm bucking for a full time overnight supervisor position, if I get it then I'll go full time, which will stink but with Dh out of work (still going to school full time tho), we desperately need the money.
You gotta do what you gotta do.
One thing, it is unreasonable to expect to be able to watch little ones and sleep at the same time. DD was 4 and a bit when I started overnights, and it was rough for her at first. At 7 she's better adjusted to it, but I have no illusions that it'll be feasible to be alone with the baby when I need to sleep during the day past the point when he gets mobile.
Fortunately I plan on going back to school next fall myself, and plan to give up the job then.