How heartily he serves me! His face loathes one,
But look upon his care, who would not love him?
The east is not more beauteous than his service (5.1.71-4).
No matter what she does, I cannot help but continue to feel sorry for Beatrice throughout this play. When I was reading, I was startled by this passage and had to read it a couple of times to fully understand what was going on. It seems to me though, not terribly out of left field that she would come to feel this way about De Flores. For all that he has put her through, out of all of the men in Beatrice's life, he is the only one to actually look out for her, however potentially nefarious his intentions. Her former fiancee was so removed from her experience that he was completely unaware of the fact that she no longer loved him when it was apparently very obvious to his brother, who was not planning to spend the rest of his life with her. Beatrice's father never seemed to listen to her when she complained about De Flores, and Alsemero seems completely useless and tested Beatrice to make sure she was still a virgin as opposed to trusting her. De Flores is the only man in Beatrice's life who does what she asks, and in this instance who comes to her rescue when she doesn't know how to fix all of the messes that she has made. Even though it may be off-putting then, I don't think that it is so ridiculous that when everything in her life is falling apart that Beatrice would start to look favorably on the one person who it seems is invested in helping her not drown in the weight of it all.