Hi Sage. I like your user name. I've used the same one on another site.
To answer your question, I think she probably has one of the cluster B (dramatic) personality disorders, maybe histrionic personality disorder. Compulsive lying and an erratic need for attention from others tend to be part of these disorders. At any rate, it's obvious she has serious issues. If I were you, I'd be polite to her but try to keep my distance. With the way she behaves, getting close to her will most likely lead to trouble. It's kind of sad because her issues probably are related to the way she was raised, and she probably is unhappy a lot of the time. But if you try to hard to be understanding, she'll just try to use it to manipulate you. She really needs to work with a professional to fix her problems. Often even professionals have a hard time dealing with these types of people, since people like her often aren't interested in changing the way they relate to others. Somebody who's not even trained to deal with it is going to run into even more trouble.
If you're feeling bad about not being friendlier to her, keep in mind that you probably wouldn't even have had this much of a relationship if it weren't for her issues. She's not somebody you happened to meet and hit it off with. You're one of a long line of people she's sought out so she can be the center of attention. She's not looking for a friend. She's seeking out inappropriate attention wherever she can find it. You certainly don't owe her anything.
“This planet has - or rather had - a problem, which was this: most of the people living on it were unhappy for pretty much of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movement of small green pieces of paper, which was odd because on the whole it wasn't the small green pieces of paper that were unhappy.” ― Douglas Adams, The Hitchhiker's Guide to the Galaxy