As no one has yet answered your query, please take a look at this thread //www.curezone.org/forums/am.asp?i=1297467
which may give you some guidelines as to where to get help. I hope it all works out well for your gf

You need to confront her first. There is a reason why the cliche exist: the first step is admitting you have a problem. She will probably be angry and frustrated. You have to understand that eating disorders are about control. She feels thatby throwing up she is gaining some control over her life. She needs help, counseling and support, but first SHE needs to admit there is something wrong with her behavior. I hope this helps.