First, don't breed her again. If on the second attempt she is still having premature kits, I would not risk it.
Second, there isn't a whole lot you can do. Monitor their weight, make sure they are nursing, and then wait. This will be one of those judgement call times. Since they are premature, do you start hand feeding at least a little to be sure they are getting food? Or do you wait for mom to feed them so that you don't hamper her milk supply. Premies rarely have any reserves to fall back on, so be sure to keep a close eye on them.
Check the FAQ's for the one written on kit care and lay in the supplies so you will have them handy.