My brother, may I give a warning. If she continues without regard to this request of yours be sure that she is not close to God. I do not mean to come across as judging because I know not all things like God. However, in James the brother of Jesus says that our profession of our faith is worthless if we cannot control our tongue (James 1:26). In Matthew Jesus himself says that we will be judged for every idle word we speak, and on judgment day our words will either condemn or acquit us (Matthew 12:36-37). There is good news. Paul writes in Romans 6 that sin would not have dominance over us, but we can have victory over our sin (Romans 6:14). Even controlling our tongue. This is a true and trustworthy statement. If you humble yourself before God and renew your way of thinking away from sin and towards God and Pray for his Grace to overcome sin Jesus will help you and your girl to overcome sin.
The first promise in the NT is Matthew 1:21 "You shall call him Jesus, for he shall save his people from their sins".
Take heart, there is tremendous hope for this girl because she is still alive. The best way for her to change is to see the light in you. Be filled and overflowing by the Grace of God and she will see that and by God's grace be convicted and change.
Take heart, God knows all details of your situation, and take this promise that is pleases God to shower you in his saving grace.