Closed faced reels are a pain, I always try to get a kid to use a simple spinning reel and rod. I prefer to use a 20# to 30# braid depending on the size of the reel/spool as it gives great abrasion resistance and since there is no stretch in the line, a late hook set or a weak hookset will be enough to set the hook.
Depending on the age, I try to keep rod length short so that they can cast for themselves without needing a lot of room to avoid hitting others with the rod. When it comes to cat fishing, you do not have to go expensive on the set up.
Capt. Craig Copeland
2013 Nautic Star 2110 Shallow Bay Boat
Nautic Star Boats Pro Staff (nauticstarboats.com)
Redneck Fish'n Jigs Pro Staff (redneckfishn.com)