It was quite possible that Meg may have pushed Jo too far when she let loose with all of that information. Jo didn't even say anything or make a sound when she slammed herself into Meg, trying to knock her onto the ground while she slashed at her throat with her knife. The blonde huntress was beyond rational thought right now and was functioning on pure rage-fueled adrenaline. She kept trying to do damage with the knife as she kept punching at Meg wherever she could get her fist to land. She no longer thought about the fact that Meg could kill her easily. She just wanted to do damage, to make Meg pay for everything that had happened and every lie she was trying to convince her of now.
Jo had never lost her head in pure rage before and later she would be surprised at her actions. For now, though, she ignored whatever ever thoughts or pain she might have and was focused on hurting the demon as much as possible before she did whatever she was going to do to her.