You're right. I just did a run where all I did was meet her, fight Elizabeth Bathory, talk to her just once at the Mushroom Village, and she really did show up at the hotel. I'm chalking it up to me confusing the saves that I used.
Thanks for the ton of advice. I would've never known about luck being such a useful stat since it's usually just a dump stat. I didn't really search up on DLC 2 (and by extension, 3) because I was planning on going at it blind but I'm starting to hit a roadblock. Who knew I couldn't just Kishingatana or Anchor my way out of everything. Though, I guess I should've expected it because I was forced to explore options and use spells for the first time with Kuti. As for my stats, it looks like I could hit 10k luck faster than I expected: with double Black Goats + White Rabbit, I could already hit 9927 luck, and aside from ATK, most of my other stats are around the 8k-9k range. I'll give the Boss Rush another try, I got up to the dragon one with the false win but I immediately lost the next batch. Also, thanks for reminding me about the True Vorpal Sword; I kinda forgot to list it down.