D.
I really don't think I understand this business model. What are you paying for? Anyone can get together with friends and exercise in the park for free. If you're paying for an exercise class you sort of lose the "guilt free" out if the baby doesn't cooperate. I can understand a group of ladies getting together and taking turns watching the kids play on the playground while the others walk/run the track or whatever. I also understand how it motivates us to show up if others are expecting you to be there. Anyway, this sounds like a good cooperative arrangement between mom's in the same situation but I wouldn't pay for what would surely be a workout filled with constant interruptions by the babies. I feel like my gym membership has value because of the facilities like the kids club, pool, jacuzzi, as well as included classes staffed by experienced trainers.
Sorry if that's not what you wanted to hear.