Please help me with this girl...please?

[Johny]

This girl started talking to me on Twitter based on common interests in music, and she messages me every single day and is like "Hey blah blah"

She says things like "Any girl would be lucky to have you. "
"I love talking to you. "


She lives across the country, but is going on vacation about 3 hours from me and she asked me if I wanted to hang out while she's here.

She's a freshman in high school and I graduated last year which is really weird, I feel like a weirdo for even talking to girls that young but I don't want to be mean.

How can I get her to stop talking to me? She even found and added me on Facebook too!
Shoot I put this in the wrong category