I had my VR surgery at a children's hospital (Texas Children's in Houston) when I was 25. It was great. True, I was among the oldest there (there were actually two other adults to pass through while I was there, though I didn't see them), but the staff were all wonderful. I always got funny looks when volunteers would come to the room to suggest "arts and crafts" and see me in the bed.
They would walk in talking, then stop mid-sentence. It was funny. But everyone was great.
The thing I loved most was that they not only allowed, but expected someone to stay with me. When I go to adult hospitals, that's not always the case. Plus, the rooms were all private, with a day bed for my husband to sleep on. This may not be the case at your children's hospital, but it was for mine.
Granted, this was just my experience at THIS children's hospital. I had my first open heart at another children's hospital (in Dallas), and I wasn't nearly as impressed. Of course, I wasn't there as long either (three days, half of which I was in ICU). At that hospital I was crabby because I had to share a room with an infant who cried all night long!
And his mom didn't stay with him at night, so there was no one there to try to calm him down. If your hospital has semi-private rooms, try your best to get a private. Sharing with kids can be a HUGE pain when you're trying to recover.