Besides the fact that it seems like the ACT may be a better test for her, jn many ways the ACT is easier to study for. It’s a bit easier in terms of material but requires speed. For most students, it’s easier to get faster with practice than to master harder material. (Not all, btw – some find the speed requirement too stressful.)
The classes are likely to have a different focus depending on the test, so prep for the test she plans to take. I agree that a good tutor is likely to be more helpful than a class. (And I say this as someone whose kid did a class…)