Loads for you to do ...I´ll start the list off and no doubt others will follow
Punta Jabillo beach in CT is really safe for little ones as it is a sheltered cove.
Ranch Texas in PDC
Bird Park in the North of island
Lanzarote a caballo in Uga (between PDC and P
if they like horses.
Couple of boat orientated things in Puerto Calero (submarine etc) but youngest might be a little young.
Or they could even come to SARA Animal shelter one morning (five mins by car from CT) and walk some dogs or play with the kittens.