Yes the Israeli visit was a big error of judgement on her part. That only had repercussions for her. But if she was let loose with foreign policy the errors of judgement are likely to involve all of us, so I would steer clear, even as a shadow appointment.
As for her relationship with the Israelis being something that could meaningfully help resolve the present crisis, if Netanyhu isn't listening to the US president when it's USA that supplies their offensive and defensive arsenal, I very much dount he's going to be influenced by a UK shadow minister,