The only one i can think of would be the Paradiso Hotel/apartments you should find many discussions on this forum about it. Its not right on the beach but within walking distance. But its so easy to get about in the area i would'nt put the priority on Fishermans beach, any apartments within the Albufiera/Sao Joao/ Praia de Oura area that run kids activities would be OK. Any further help just ask.

Mandii wrote

The only one i can think of would be the Paradiso Hotel/apartments

I think she may have meant "Paraiso". If so,these apartments are in the Thomas Cook brochure and, from what we saw at Christmas ( although they weren't open at the time) the kid's facilities at the hotel are really extensive.