I feel the same way; really don't like anyone invading my space for too long! It's hard to explain to her because people who take advantage of others don't want to "hear" that.
I couldn't live like she does -traveling from friend's home to friend's home - and i doubt you could either. If she doesn't "understand", you may have to forfeit a friendship. But don't worry too much about her...she seems adept and making new friends...and apparently likes it that way, rather than keep a good full-time job and establish a residence of her own. Thank God she doesn't have children (I assume from your post)!