Yes, I remember you mentioning this a couple of weeks ago, so I was quite surprised when I witnessed it for myself. Apparently they don't like taking on larger birds such as crows because there's a danger of getting their plumage damaged which would seriously undermine their ability to hunt. It probably doesn't help that the crows tend to hang around in flocks, so in this instance, she would have been seriously outnumbered if they'd actually attacked her.