No matter what she should take 1 day off each week with ZERO exercise. Even if her classes are low impact the body needs rest. The other factors that determine if she needs to take more then 1 day off per week are her age, her job, possible injuries, how many classes she takes per day, etc. Lots of factors here. Some people become addicted to exercise but there are certainly worse addictions! So, for the moment I suggest 1 day off per week no matter what. I don’t want to see her burn out and quit.
Best of luck!
Coach John Kane CPT