I need your feedback on starting semi-private personal training sessions.

My business is personal training of women in their homes or offices. A couple of current and former clients want to do all semi-private sessions, or a combination of one-on-one/semi-private. For a percentage of my hourly rate, the owner of a local martial arts studio is allowing me to use his space during the day when it is not in use. I was thinking of offering class on a Monday morning, but am wondering if two mornings--perhaps also a Thursday--is better. The series of six weeks would be pre-paid. Maximum number of participants is four. Format is a circuit class using my portable equipment--resistance tubes, stability ball, free weights, step, foam roller, gliding discs, etc. Rate per person per class is just a little more half of my one-on-one hourly rate. No refunds are given for missed classes. My business webpage has a link with reference of offers to my Facebook business page, where the offer will be posted. Your feedback on this proposal is needed and appreciated. Thank you!