Support isn't exclusively stating you explicitly support genocide and nothing else. The majority of support is going to look like people who refuse to mention anything at all about the genocide but show up to tell people AGAINST the genocide that their actions, methods, wording, and choices are wrong. that's about the strongest public support you'll see. if your argument is no one can call it support because she isn't saying out loud 'I support the genocide in Palestine' you're making a very bad argument. Historically, a supporter of atrocities is going to tell others to sit down and shut up, it's going to claim nothing is actually happening, it's going to argue that the law allows the abuse or forbids aid and that's just because it's the law, or something else along those lines, it's never going to be someone saying they support the genocide directly.