I can't believe at the missed business opportunity here. It sounds like she could have easily pulled 7 figures from running those classes. Even if she hired a "business manager" of sorts for a cut to grow her lessons, it would have been a really financially rewarding endevour.
One thing that boggles the mind is how many people were not planning to request a refund! I couldn't imagine spending $500, not receiving what I paid for, and being okay with that.
Honestly, it still surprises me how much some Instagrammers make. A friend of mine runs a food IG (~3,000 followers local to the area) and pulls in 1-2 free meals a week, effectively funding the content creation costs. Another friend is in the ~40,000 follower range and gets paid something like $50-$200 + meals for each event -- you just go and book a time slot on their website.
Yet for me, IG feels so fake, but there are enough repeat advertisers that there must be real users out there who follow and purchase influencer recommendations.