I'll preface this by saying you shouldn't take anything I say too seriously, because I don't know what is best. What works for someone might not work for someone else..
I think the main benefit of schooling is that you get taught whatever is being currently used/practiced in the industry, so that when you're done with it you can expect to seamlessly transition into the workplace.
It's the school's job to know what the student needs, etc. So if you aren't going to school, you have to do extra work figuring all that out, and you also may not have access to everything, such as specific tools.
That being said, I'm a self-taught artist, and managed to get into the industry when I was 16 or 17. Straight out of highschool I moved and work full-time for 5th cell media, but I had been doing work while I was in highschool related to game-art too.
There were less people doing what I was doing back then, so maybe it was easier than it is now, and also technologies have changed- so expectations may have risen.
A lot of people who have gone to school and gone to work at game companies have also gone on to a more independent route, because chances are a person isn't going to be able to fulfill all their creative desires creating what others want them to create instead of what they themselves want. I know people who have worked at major game companies who are now choosing on their own to do their own thing instead, because for them it is more rewarding that way even though it doesn't pay much if at all.
I feel like, if a person isn't doing what they want to do already, what's going to make them continue doing it later?? Everything I have done has always been an extension of the things I've already done. I've been doing art all my life, and game dev related stuff for almost 20 years now. As it looks, It seems like I'll continue doing it, but in what shape or form, I'm not sure- but I'm at least doing it.
I'd say whatever helps her do what it is she is doing, would be good, whatever it is. But, I don't have a kid, and I'm only 30 years old with 2/3rds of my life inside my games/art- what do I know about life..