If you're concerned then you're concerned. There's no "she should be free to do whatever she likes". That's not what a relationship is. The only people who tell you that are shady people who can't be trusted.

You are not a hostage here. You can end a relationship for any reason. You can be unhappy about the way she chews her food and ask her to change it to stop annoying you. You don't have to be afraid to voice your displeasure about something.