My gymnast daughter is 100% on her own for workouts- and she chooses to work out five days per week, ranging from 45 mins to 2.5 hours. I have never had that kind of drive for anything physical, especially not totally on my own. I think 3 hours at a pop would be too boring, too lonely, too much all around. My daughter who is a dancer has zoom classes 3-4 hours per day, 5-6 days per week. It’s less than the hours she was dancing in person, and she’s incredibly diligent about it (even completing her extra workouts alone), but she’s also said it’s just way more tiring than the more hours were in-person. It just feels different and I completely understand that. Everything feels different remotely. My older daughter’s college classes meet live over zoom. Same time, same people, same exact class format- yet my daughter (who LOVES school) is far less motivated and swears she’s getting way less out of it. I personally wouldn’t push your daughter. I would talk to her and see how much she can do and still find joy in it.