the 500? or the add on card? delicate?
Sorry for the late reply, the A500 is a sturdy beast so no of course not but the ram/ide upgrade clips in the CPU socket and has two small wires to solder to the motherboard, potentially if the machine was bumped or shoved something could come loose so not ideal for a machine that will be used by youngsters.
I'd just get a big box of used floppies and let them play the old fashioned way! Most Amiga's have lots of Disks I'm sure they'd love to get rid of so it would be no trouble finding them.
I give the same advice for the ACA500 which was mentioned earlier in the thread, again a cracking bit o kit but it's exposed outside the machine with delicate CF card slots, I really don't think that's suitable for a 7 year old.
Some of the best racing games, Stunt car Racer and Lotus 2 both work great on an A500 as do most of the best Games. AGA only make up a small percentage of Games for Amiga.