Perhaps some more stimulation for her may be good could she be bored when she does this keep her busy playing take her out to play grounds ,having fun, I have heard of this before so if you look at the related discussions you may get more input from others, I think it would be a good idea to speak to her Doctor regarding her swallowing the hair.
my 2 year old also pulls her hair out all the time an puts her dummy in her mouth.. i am now looking on internet to see why she may do this