fresh fruit and baked goods like you've been doing, plus a couple deliveries of hot meals at dinner time (unless she's getting free meals and they're decent). a couple lighthearted things to read while sitting in the NICU or while resting (magazines, light novels, even a couple of childrens books to read to her baby). a loan of an ipod or small laptop with some movies or music, even better if she has access to free wifi somewhere, if she doesn't have something with her. chapstick, scent-free lotion and a water bottle to keep in the NICU.
personally, i wouldn't have cared much about the nursing tops and bras... in my NICU, we basically wore pjs or very relaxed clothes and there were plenty of places to pump... nursing tops are more for when you're out in the world and want to be discreet.