20 is resonable, 30 maybe. But i think she is under modelling contracts straining her back and probably cant commit to both worlds. But then again, i think people would sub even for workout/modeling tutorials as you said, if it is onlyfans doesnt mean it has to be erotic or anything of that sort... i mean there are ASMR models there with 50 usd/month subs doing nothing but chew gums on a microphone :D