Compulsive Liar- HELP

I have a friend who tells me things but then changes the story ever 10mins- to add to this she tells us all differnt stories - usually due to the fact that she cant remember what she just told us! she also seems to have made up some friends as they atcually do not exist! she also pretends to know ppl who she atcualy has never spoken to ( i know because i know these ppl- and when i have mentioned her they have had no idea who i am talking abou- this makes me look like a fool)

She just lies and then tells us that she hates liars. We dont know what to believe nemore. I wanna confront her to try and save my friendship with her and also the relationship between her and the rest of the friendship group- however i think it may be a serious problem for her- mayb an insecurity???!!!???

How can i approach the subject and ' have it out with her'??? i cannot listen to these lies nemore- they are boring and when i have to sit there and pretend i belive its just embarassing. Shes making a joke out of us- but i dont wanna make a joke out of her trying to sort it out!
What should i do?