Lambda, if you plan on switching jobs anyway then sure, you can go for it and see what comes out of this situation.
However, from what you said it seems like this girl is an AW (as everybody else here has been pointing out) and so your chances of actually getting laid are pretty slim. Of course, the best way to find out is by actually is by inviting her out. The truth is, a girl who is really into you will jump on the occasion, a girl who is just craving for attention will make up some excuse and pass. Pretty infallible test.
I noticed some red flags, however, in your post. What do you mean by "maybe I have some feelings for her too" or " I've been a little bit too clingy lately" or "I want to get intimate with her, and maybe even more"?
When you know how she treats her BF, why would you even think about taking his place?