The scary thing about Bella was her complete lack of care. Others would have had issues with attacking a female and even moreso if said female was pregnant but Bella? Bell had none of those cares. If you were stupid enough to cross her path, if you were stupid enough to take her on, to engage her then you brought whatever consequences were coming your way on yourself. Female Bones' could have easily run and if she had? Bella might have let her go. After all she wasn't her mission. Her mission lie elsewhere but seeing as how the girl had stupidly decided to engage her Bella certainly was not going to run nor was she going to just ignore the gift that had been presented to her all but wrapped up with a shiny bow.
"Really? Because as I recall it I left six dead Muggles in your precious Ministry and your husband has been out of commission just as long. In my book that's a win win. Granted it would have been so much better if there had been a seventh dead body to add to the count and to the shock but there is still plenty of time for that to come. The extra time just means I get to properly plan how to truss up his dead carcass once it finally comes into my hands."
Perhaps Bella should have cared that Catherine Bones had basically just summoned the entire Ministry, hell perhaps even the entire Order (Merlin she hoped the Order showed, it would make things so much better in her opinion) down upon them but really, she didn't. Chaos and damage was their goal and if a few Ministry and Order member bodies could be added to that carnage? Even better.
"Shall we bet on that, sweetheart?" Before the words had even finished leaving her mouth, a blasting hex was sent at the ground at Catherine's feet, a shield flaring up in front of Bella as well. If she wanted to dance, then by all means, they would dance.