Seems to me she is keeping you around in case she does not find someone else or needs a shoulder to cry on.

As others have said take care of yourself first, if she cares about you as a friend she will learn to deal with it. But be warned the friend stuff after a relationship rarely ends up working and usually ends up in some nasty parting of ways.

Heck next time she calls tell her you are starting to see someone else, that should give her a about face.