Another vote for CaSavio here. The campsite now has an airport transfer bus direct to the campsite. I don't have details, but if you Google the campsite, the info is their in English too.
We have holidayed here several times as it is so child friendly. I don't know how you feel about cooking but if you want a break, there's lots to choose from on site and a short walk of cycle away (you can hire bikes/seats etc) you can easily reach the village with well stocked beach equipment shops and places to eat.
CaSavio site has a very friendly toddler depth pool which they can toddle/swim in and the beach is directly accessible from the campsite.