One of my grandsons has spina bifida and I've spent many nighttime hours with him so my daughter could go home to see her other kids. We all live within 45 min. of our Children's Hospital so we don't stay at the RMH. Still, you can go a little stir crazy. Here are a few more ideas.
Offer to run errands for them--pick up items from a grocery store or pharmacy, send mail, drop off dry cleaning, or whatever else might be helpful.
I loved the idea of a phone card.
Give them some disposable cameras to take pictures of their little one on good days, or take pictures of staff members they draw close to or friends they make while they are in Boston. Offer to get them developed.
Give them a couple of nice notebook and some pens. One notebook could be to keep track of practical details--med protocol, schedules, docs' names, questions, phone numbers, etc. The other could be to keep a journal of this precarious time in their lives and keep track of the personal side of things.
Take them a basket of treats--fresh fruit, specialty cookies, hot chocolate or coffee mixes, canned soup, nuts, things they aren't likely to run across in the hospital setting.
How about an inexpensive tape recorder and music. Soothing music, silly songs, books on tape for both parents and kid. If the risk of infection isn't too great, perhaps you could get tapes from your library and trade those for new ones when they've listened to them all. Blank tapes might be good, too. The could record messages to the folks back home and have loved ones send tapes to them so their little guy can hear some familiar voices. They can also record some stories that their son can listen to when they aren't with him. If they are taking turns at the bedside, he might be comforted by hearing the voice of the absent one.
Depending on how long they are there, offer to pay for a haircut and give them directions to a local shop.
Bring some nice shampoo or bath beads. It becomes so important to learn how to relax, but that's something you don't even put on your list when your kid is sick.
Don't forget to ask directly what they might want. Or mention some of the things the we've come up with and ask which they'd find most helpful.
It sounds like you'll be able to offer some wonderful encouragement and moral support to this family in need. I will pray for them today.
You have a good heart.
BTW, how are you feeling? How close to your delivery date will you work?