It's good for the kids (and doesn't hurt for anyone, IMO) to know how to change a tire. I would appreciate any adult in my kids lives that just included practical info. Oh, wait, mine DID have many adults like that. It sounds like maybe she knows the kids through something with school, and I will agree that schools aren't responsible for teaching basic things like this, unless it's related to the class. But, putting an incident to good use is not a bad thing.
Considering that the kids this person knows are probably driving cars paid for and maintained by their parents, she's doing the parents a favor, too.
My friends and I have taught a few teens how to change oil, flush radiators, change brake pads, just basic stuff. I don't even think it matters if they are never going to do any of those things. In some cases they might, in others, it might just be good to be around an adult who will spend time with you. I've also volunteered at a church in Casper, WY that taught low income people (mostly single moms) how to change oil, their tires, when to buy new tires or brakes, etc. .