I have been to a few places recently and should share so anyone visiting the area can accommodate the kids.
Swiss Sheep farm - Newish tourist attraction near Silverlake. Super place for kids to visit. Animals really well taken care of plus lovely grounds to walk around in.
A few miles up the same road is the new Ramayana water Park.. Great fun for all ages. Slightly dear and the fact they then charge for lockers on top really annoyed me but a great experience for a family. No queues largely because its far from the beaten track and most Thais won't shell out that much or are petrified of getting "black" skin.
Harbor Mall has loads for kids to do and is reasonably priced. Compared to the rip-off kings that is Central its well worth a trip. Just on the s'vit side of Central road.