Would it be particularly wrong to ghost a girl who loved my by moving across the country?
Are you serious? Would you say the reason you're considering this is because you don't love her?
No, because I'm tired of her. I want her out of my life.
You shouldn't just ghost this girl. That's very rude and childish. Don't do that.
I'm not a kid, I shouldn't have to put up with having a girl around.
You should just tell her that, then. Let her know you're not interested instead of running away from your problems. Otherwise you're just showing far too much disrespect for her.