Don't know if it will help, but has she tried co-washing? (washing with conditioner). There was a thread somewhere on the Dis about it not too long ago. I've been doing it, and although I don't have totally frizzy hair, it's helped my hair to be very soft.
White Rain is the recommend product. I also got a great deal on Wen (google it - it's supposedly really good) through buying proactive products, and I'm currently using that too. When my good deal runs out though, I can't justify the price. White Rain conditioner does not have an ingredient (I can't remember what it is) that most shampoos and conditioners have. You scrub your scalp with the conditioner for a couple of minutes (it won't lather, but it will be very creamy), then I put more on the rest of my hair and let it all sit on the hair while your doing everything else in the shower. I then scrub the scalp again as I'm rinsing it all out. People swear by this method. I've been doing it for a couple of months, and I'm very happy with my hair.
It can't hurt to try it. Also, of course a good leave in conditioner afterwards is important. I've always liked frizz-ease products.
And every few days, a deep conditioning treatment that she leaves on for a while would probably help relax everything too.
If nothing works, I'd try a bit of a different hairstyle for now... wearing it partially up in some way, etc.
Good luck!