Hmmm, spirituality vs psychology. The magickal practioner in me says its possible that there was some sort of possession involved. Seizure without medical reason can be a symptom.
The student of psychology in me says this could all be signs of a very severe mental illness triggered by the original rape. The second assault could have been self inflicted if there were no witnesses. The incomprehensible babble and belief of a second personality within could be signs of acute schizophrenia brought on by trauma (which can be cured if assessed early).
Hell, this is a tough one! I'm so torn!
Ok, buy a Saint Benedict's medalion, have your witch friend bless it.
I am not Christian, but that doesn't stop me in recognizing certain people as remarkable souls, and Benedict was one of them. I have used this medalion against the worst I've encountered and nothing has ever been able to get pass this amulet. Find a nice one in silver or gold and have her wear it AT ALL TIMES. Even when bathing. If the amulet makes her ill or she constantly removes it, then your friend may be right and may not have successfully removed the spirit. Do NOT tell your daughter any of this! The power of suggestion may cause her to act if she is indeed suffering from trauma.
IF she's fine, wears the amulet BUT her symptoms return, then it is NOT a spirit and your daughter needs to see a good psychologist immediately. Try to find one that doesn't believe in using drugs unless absolutely necessary, or even suggests herbal alternatives. The sooner your daughter is helped, the sooner she can move on with her life in a positive and healthy way.
And lastly, when all is said and done, you may wish to look into soul retreival for your daughter. Look for an authentic medicine man or woman, there are tons of fakes. In such cases as rape, the spirit tends to get extremely damaged and cause many problems for the mind and emotions. It's symptoms are identical to disassociative disorder with the addition that they feel forever as if something is missing within them, that they don't feel whole, etc. And I feel your daughter displays that perfectly.
I'm very sorry for what happened to your daughter. I'm sorry I can't help more.