Buy them gas cards, restaurant giftcards, or a little cash to get food at the cafeteria or snacks they can store. (Snacks would've been the last option for us as there was no food allowed in the rooms).
Cook them a meal and go out of your way to deliver it hot and ready-to-eat on their schedule. By the time parents might get home at night, there is no time to prepare or even cook a freezer meal, but they will most likely be hungry!
Babysit the other sibling(s). ALL DAY.
Offer house cleaning services.
Run errands for them.
Offer to do their laundry.
Buy them extra cell phone minutes, depending on their plan.
Find out if they want visitors and visit them (but only if you are completely healthy). See the baby if they invite you but not as a spectacle sport. Then visit again.
Ask how they are really doing and be prepared to listen. Every day, sometimes moment to moment is different - they might've just gotten some disappointing news, they might be processing some new information, they might need to cry, or vent, or even talk about something other than NICU life! It all depends on the day. Or the hour.
Don't bring flowers.
Don't look at them sideways if you just washed your hands for 3 minutes and they want you to use hand sanitizer.
Don't remind them to take care of themselves. Most likely they've already been told this (several times) but it's an impossible thing to choose between yourself and your child at this point. Let them do what they need to do.
Don't be offended if they need something you can't offer - don't push, but let them know how to get ahold of you and what you are willing to do.
And after they come home? Offer to clean their house or do their laundry or bring them a meal! It's just like bringing any new baby home from the hospital - it's just as or more overwhelming. Feel like a lot? It is. It's a long road - walk with them down it.
Are you a NICU nurse? Here are a few do's and don'ts from a NICU mama:
Always ask if they want to be involved in baby care as soon as possible. Most likely they will jump at the chance. Ask every. single. time you can. Every diaper change. EVERY ONE.
Don't do anything unnecessary without the parents' consent (read: medically unnecessary, obviously). Parents have already had to grieve so much. Please don't snatch away the small firsts they can have. Unless you discuss otherwise, let them do the first bottle, dress their babe in the first "real" clothing, etc. This is unimaginably important no matter how normal, every day it may feel to you.
Ask if they have questions. Answer questions as thoroughly as you can. Don't give them more anxiety but don't sugar coat your answers either. If you don't have an answer, don't make an educated guess. Get the NP or ask the neonatologist. If they ask the same thing again, explain it again. It's an overwhelming amount of information on very little sleep and high emotion. Soon enough they will be the expert on their child.
Respect the parents' wishes. Follow them as closely as possible. If you aren't sure and need to know, call them.
Treat them like real people; don't talk down to them.
Night nurses, make sure they know they can contact you at any time! Encourage them to do so.
Help them advocate for themselves and their child. Be honest but be on their team.
Did I miss anything? Feel free to share your experience in the comments!