Is it normal my chick friend always messages me when she's drunk?

I have a chick friend, we went through grade school together all 12 years and never spoke one word to each other. She was never hot in school and I guess, well I was attractive. I ran into her a few months ago and now she's really hot, I got her number and we started texting. She has a boyfriend of 2 years, but she sort of flirts with me. I can't tell. She texts me most when she's drunk, or late at night. I recently moved out of state and have a career. I was texting her one night and telling her about my new place, she starting talking about coming to visit me and talking about drinking with me. It sounded some what "flirtatious". Is this normal? Never really had a chick friend before.