I think were ever you go in Turkey the kids will be fine, we have been taking our Grand children since they were small, they have great fun in the day around the pool, days out on the boat and there is a couple of big aqua parks in Marmaris, transport laid on, pick you up from your hotel and drop you back later, so no problem.
Lots of shows in the evening, kids always welcome as the Turks love them
and will go out of their way for you and them
Marmaris is mad, Icmeler, just down the road, loads to do but not as hectic.
Think Hisaronu and Olu Deniz a bit to laid back to keep the children happy for long.
Have a look at the Marmaris palace, just between the two.
My grand children growing up now still love to get back to Icmeler and have some great memories of the people, enjoy.