Didn’t take a genius to deduce that the Ursa wasn’t done with her. Apparently, hurling a wheelbarrow in somecreature's face made her top of the list. That Ursa was out for blood: Specifically, HER blood! She wouldn’t be subdued until she could floss bits out of her teeth with Twilight’s bones. Could be why the royal guards’ distraction only lasted as long as it did. Unlike the princess, they just weren’t interesting enough to be dismantled bit by bit. Or perhaps the Ursa was simply saving them for later?