>>533941846
>>533942731
In her defense, it's been like 3 days in-game.
She hardly has time to ask questions with all the crazy shit happening.
It's also hard to separate our knowledge of Kris, the Soul, and meta-knowledge from datamining and the website.
Susie's blind to half the things we see.

I admit it's a weak point in the story, though.
There's a lot of media, especially episodic stories like Deltarune, where the mysteries rely on a key character being dense as concrete, and it gets frustrating as the story goes on.
Steven Universe comes to mind.