I have no suggestion for when would be a better time to bring up the animal feeders, especially since it hasn't worked for the other neighbors. While it does sound like you're countering, given you stated the other neighbors have been rebuffed in their attempts to address it with her, I don't see what other option you would've had in trying to get her to stop feeding the wild animals. I wouldn't take down the windchimes then hope she'll return the favor; she has already indicated she's not willing to change anything for the other neighbors.
I once had a manager who asked his colleague if she could provide some information to him pertaining to her section. She was frequently an unpleasant and unreasonable person to work with so she stated to him, in her unpleasant fashion, that she was too busy to obtain that information and to take care of it himself (I think it involved numbers he needed from her section). A few days later, she approached Manager and requested he complete a document for her. His reply? In a nice tone, he said to her that he was too busy to do her document as he was still trying to find the numbers he needed from her section. He wasn't lying, he wasn't being rude and he wasn't countering; however, he did get his point across about not being willing to help others. He said she gave him a nasty look, stomped out of his office then returned a few moments later with the information he'd first requested. He then told her something like, "Good; now I'll have time to work on your document."