Looking a bit deeper into this it seems to have started when she reposted a meme about antisemitism on her story:
The image itself seems absolutely innocuous (at least to me), and I can see why she shared it. The issue some people have is that it's a repost from a group called Zioness, which appears to have funding from right-wing groups and is dedicated to pushing the message that anti-Zionism is antisemitism into progressive spaces:
(That second thread is quite long but it's worth a look as it goes into the group's messaging in depth and talks about why it's a problem)
There isn't any evidence that Jessie Ware has looked into any of this particularly deeply, and though a closer look shows Zioness to be an pretty dodgy organisation personally I think she was just sharing a meme that spoke to her as a Jewish woman. Or maybe I'm wrong and she's a rabid Likud stan, who knows?