Hair franchises are kind of tricky, kids hair salons are even trickier. Hairstylists would never buy a franchise and loose control, the audience that buy hair franchises are not hairstylists that can jump in to fill when somebody quits or call out and trust me, the type of hairstylists that work at chain salons do all the time. The industry itself already has high turnover, most hairstylists do not like doing kids hair either. You are correct as kids hair salons typically only work in more affluent zip codes, but at some point Timmy is grown and can’t fit inside the spaceship seat anymore or parents decide its time to take their kid to get an actual decent haircut elsewhere since they can afford to, the kids salon was more just a place that welcomes their screaming child and offer to blow bubbles in their face and keep them distracted. For reference, the hair franchise I knew had to make 6k a week to break even, hair franchises usually average 10-15% profit, imagine how many heads you need to cut, they eventually close because they couldn’t keep returning customers since quality at chain salons are bad or get staff to show up and you only collect revenue when there’s body to be there to provide services. Your friend aquired an existing salon so maybe system and clients were already in place.

I’m not sure if there’s a big enough market for this, seems like there’s a higher success rate to sell car parts or car related stuff to car enthusiasts or coffee to coffee drinkers instead, coffee for car enthusiasts seems very specific. I can see it working better selling coffee to locals and maybe offering it at car meets as one part of community thing.