A.G.
Check out the website
www.positivediscipline.com
I can not explain the "miracle" that has happened in my household since reading their book. I have to say that it sounds like her daughter is looking for attention anyway she can get it.
It would be best for her to give her daughter lots of positive attention: extra hugs, story time, special time between mommy and me, one on one activities, tickle time, etc (of course when she is not behaving in this way) to PREVENT her from hurting herself for attention and the episodes should stop.
I know one of my sons started to hit his head on the wall when he got mad and I used to tell him "Don't hit my baby!!" and give him a big hug as though someone ELSE had hit him and start tickling him, etc to distract him and he stopped doing it. But, the key is to prevent the need for attention that is causing the behavior.
The book and even the website offers lots of ideas that should help her.