I'm not entirely sure how anyone expected her to react differently, frankly.
Biden and the Democrats misunderstand her base. They (wrongly) believe Joe Biden is complicit in genocide. The problem with that is you can't "lesser evil" it away like most policy issues. People aren't going to vote for the person who would commit genocide even if its less than their opponent, and most would rather vote 3rd party or stay home at all. Instead of trying to paint Trump as worse on the issue, the Biden campaign needs to assure these voters that they aren't or doing anything remotely close to genocide.
Basically this. The only thing acceptable would likely be a public repudiation of current Israeli policy in Gaza coupled with some kind of "consequence", which frankly, wouldn't be that much of a stretch at this point.