I just going to suggest this. However for TS,  is your girl 2nd personality disturbing your relationship? How is the 2nd her if compare to the true her? If you think it's disturbing you, then you can consult psychiatrist. Maybe she will go for observation, and might given drugs to control the brain activity. Or maybe it's like a childish behavior. Psychiatric is a world where there is nothing true or false. I suggest, tackle her main problem. Ask about here stress, pamper her, give more attention and observe her. If still no changes, then it must have been psychological problem. And monitor when will the 2nd personality come out? During stress only, happy or even during sleep. Most of the case I seen is when the patient realize they are ill, they won't hesitate to seek treatment, but WITH SUPPORT. Without support, it's seem you just want to fix her for your own good, or she's not the same person to you like before.