I also think Marigold is being judged much too harshly here.
As I've said before in this thread, she just does not now how to deal with this kind of situation (remember how she acted when Francis showed interest in her and there was the prospect of having to talk to him alone, although she didn't know him at all - and they had not been in a fight for ages before that).
Also, Dale is not really innocent in this. Remember how many snide remarks she had to endure from him. I actually thought it was funny most of the time, but Marigold might not have, since she has little self-esteem and lots of experience with being bullied. A lot of those time she reacted quite well to that, though. I think Marigold secretly would like to appear cool and not much affected by anything Dale does, but is so nervous about it that she does not know how to pull that off properly. Of course, the Hissss is a little silly. But who isn't, once in a while?
I really don't think Marigold hates Dale at all, much less because of WoW. To me it seems much more that he makes her nervous and she doesn't know how to act around him.