Matched by need
Fewer camps handle this well than claim to. The questions are whether children genuinely train, whether there is anything for a non-training partner, and whether the accommodation suits more than one person.
Child sessions and adult sessions being on the same timetable is the detail that makes or breaks a family trip. Confirm it directly.
3 camps
Bang Tao, Phuket / Mid-size camp
Based on the north-west coast near Bang Tao beach rather than in the southern camp cluster, which changes the whole trip: quieter beaches, more of a resort setting, longer drive to the Chalong and Rawai scene.
Chaweng, Koh Samui / Mid-size camp
The main established training option on Koh Samui, running a mixed programme with fitness classes alongside Muay Thai. Works well for a training-and-holiday split, or for someone travelling with a partner who is not training.
Pattaya, Pattaya / Large camp
Large resort-style training centre attached to the best-known equipment brand in the sport, with on-site accommodation and food. Polished and self-contained, which is either the appeal or the drawback depending on what you came for.