Keeping the brand in the collective zeitgeist - even if you didn't buy anything - brings Rowling money through word-of-mouth marketing
My personal consumption without giving her money does nothing to support the brand or market the product unless I go around advertising it for people. In which case it was the the purchase or the advertisement that are the problem, not the consumption itself. If I pirate a movie, a game, an audio book, etc. and don't go around talking up the property, I would be giving nothing either directly or indirectly to Rowling or any other producer of the content. Matter of fact, I could share access to the pirated materials to make my direct associates less likely to go out and purchase them on their own behalf, arguably denying them purchases they may otherwise have received from more detached and careless people in my circle. But that wouldn't stop people from hating on the consumption itself. I think that's silly.
Again, I don't disagree that providing financial benefit, vocal support, etc. to a hate monger is, at minimum callous negligence, if not complicity or active support of the hate mongering. But I do not think that separating the content from the creator(s) (particularly content that has deep personal and cultural roots for many, and has outgrown its creator in many ways), getting ahold of the content without financially supporting the creator(s), and consuming it without marketing it to others is to be in any way complicit with the creator's/creators' behavior and views.