My mother works in a paediatric hospital. Every year the renal department has a party for the kids, mainly those on the ward, frequent stayers (those on dialysis etc) or past patients (normally those who have had transplants and are still under monitoring. They also invite siblings of these children. It's a buffet, disco and visit from Santa (parents provide the presents)
My mother always invites my 3 children - who have sometimes gone in the past. Other staff members children can go, but I don't *think* any other grandchildren go. Is it rude to take them.
In case it makes any difference, my middle child was born with renal problems, but has never been an inpatient on that ward. She's mainly been dealt with as an outpatient and her one inpatient stay was at a nearby hospital where the consultant has a satellite clinic once a month. She was discharged from their care earlier this year