I wouldn't say that, if the relationship didn't mean anything to her, she would break it off. But apparently it does, she just wants to have her cake and eat it too...
Now I don't know how well you should take being her back up plan, but that's completely up to you =/
Don't listen to me though, I haven't been in a relationship in about 6 or 7 years, what the hell do I know?
--I'd rather be a could-be if I cannot be an are;--
-- because a could-be is a maybe who is reaching for a star.--
--I'd rather be a has-been than a might-have-been, by far;--
--for a might have-been has never been, but a has was once an are.--