Beginner swimming for my two daughters, who refuse to share a pool with 6 year olds

My girls never learnt to swim properly and now both want to, one in middle school and one in high school, which is great. Problem is every beginner batch near us is full of small kids, and they've told me 'asalu kudaradu', no way are they splashing next to UKG children. Fair enough. Anyone know of a beginners' slot for teenagers, or a ladies' timing where a coach takes two or three learners? Weekday evenings or early weekend mornings both work.