[imported_The Vibesman]

Good. She understands you or she doesn't.

It's not uncommon for people to get irrational when they are discussing things like this. If this is the case, try to calmly and clearly point out where she is being irrational. If she continues, tell her you're not going to discuss it unless she's willing to look at all sides of the argument. If that doesn't work, tell her you don't like games and to f**k off until she wants to be an adult.