Hello,   I suggest you read Xavier Amador's book, I Am Not Sick, I Don't Need Help because it coaches you on how to talk with someone who has schizophrenia so that he or she will take the meds and stay in treatment.   Motivational interviewing can be done by anyone and is simply the process of gaining someone's trust and then asking what her goals are, and suggesting that staying in treatment and taking the meds could enable her to achieve those goals.   Her recovery won't happen overnight.  The good thing is, she trusts you, so I believe if you read the Amador book, you'll get an idea about how to approach talking to her.   Let us know how it goes.   Regards, cb