Be aware most expats resident in either marina for the winter are a tad older than your kids
But back in 2006 Kemer used to have a very very busy winter schedule.
It included daily keep fit, cookery lessons, language lessons in French, German, Turkish, tennis (coaching and tournaments), organised nights out to the opera in Antalya, weekend mountain or beach hikes usually followed by lunch together somewhere. Film and quiz nights in the clubhouse, and even a freebie cake from the management if it was your birthday........
I am sure the Marmaris mob
have an equally full agenda and not sure if Kemer may have changed under it's new management.........possibly worth a call to each which would probably give you up to date information.