Thanks, Mack. That is a better explanation than the one I posted. Was feeling a bit snarky last night.
I've had (and still have) female friends that will talk to me in this way. Lots of "love you" this and that. I've never been romantically involved with them, but like Mack posted, it could look odd to a girl I might be dating at any given time.
Also, now that I reread your post, I'm not sure where I assumed you were snooping on her FB. The way you worded it, seems more likely this was posted on the public wall, and was not a private message. In which case, this is more than likely harmless and platonic.
In the end, if you cannot swallow your pride on this one, and you cannot trust her enough to let it go, sit her down and talk realistically about it. That is always a better option than playing sideways emotional games.