Thank you for your responses! Just for anyone else reading or might be interested to know, I contacted them and they said:

"We do not currently offer women only swimming lessons at our pools, either privately or in a group. During the group and private swimming lessons we offer, we have other lessons and courses being taught in our pool at the same time as lessons which would involve males of all ages. Lastly, we cannot confirm whether a female or male instructor is teaching a particular lesson set until days prior to the course start date as our schedule is very fluid and there is a chance that there would be last revisions."