She doesn't have to have anything to do with the attack to be called out for contributing to an Islamophobic narrative. It's not rocket science. Would it be nice if everyone was always polite? Sure, but sometimes this is what you have to do in order to be heard.
Being heard is fine, but how the message is shown can be devastating to achieving what you're hoping to convey. How they framed this was not what would help their concern, hurts their credibility with the greater public and gives ammunition to Chelsea's side, not there's. There was no scenario where angrily confronting a pregnant white lady who was apologising over and over again on camera was ever going to work to their interests.