Ok, sorry it took a while, got busy. You have actually completed all Kat content on your save file, but the bug you found, being able to do her scene at the bar again, made you get stuck in a loop. Sorry about that, but that did help me fix the bug, so I appreciate it. Attached is the save, with all errors (hopefully) fixed.
Understandable, but it's not like the MC was completely forthright with all of his family members. Finding out about magic was a big deal, and he had only had it for a short amount of time. And in that time, he had immediately been attacked by a Templar. It's understandable why he would want to keep his own family out of it, and therefore understands her point of view.
Check the future tags.