So sorry to hear about your friends child. I hate it when any child has to undergo major surgery. It will not be an easy time for them all, the child will get so frustrated and the parents will get tired and absolutely worn out with all the after care that will be needed. I don't know about special toys, I'm sure the hospital will give them advice about this. If I was in your position I would give my time to my friends and perhaps offer the parents a day off and take over looking after the child for one day a week so that they could go out and just have a break. Anyway best of luck and I hope the child makes a good recovery and the operation is a complete success.