“Well, it's pure bully psychology. She feels powerless. She is in a tough spot, and she makes her self feel more powerful by picking on someone weaker. She is mean to Anne because she can be.” (Jenny Allan)

That is marvelous, I love the bully description—it is so right for Elizabeth and the panic and entitlement issues are most appropriate. You are perfectly right, of course, that Elizabeth was never engaged, all the expectations she had and the disappointment she felt on his marriage to another were not ever legitimate in that he never proposed to her, probably never even said or did anything which would lead anyone other than Elizabeth and Sir Water to expect one. I am sure though, that Elizabeth, at the very least hoped for an offer from him during the encouraged and expected visits to Kellynch that he never claimed. I should have pointed out that although she was never actually engaged she was so disappointed at his imagined defection that it felt like she had been. I think she had these strong feelings because she singled him out while still young, as the most proper match for Sir Walter Elliot’s daughter and probably never gave anyone else a chance. That Sir Walter encouraged her in this belief was, I think, very wrong of him. It was actually, the engagement that never was and that must also have contributed to her jealously of Anne. (Chapter 1 is reference for my ideas)