Plus the doll that is very precious to Kate is almost similar to the shadow Emilyko met before the shadow house.
https://www.mangago.zone/read-manga/shadow_house/mdx/d_chapter-10/3/
It isn't just any other doll in the room. I could say maybe because it looks similar to her that is why she treasures it but even so, it looks like her attachment to it is very strong.
Like she had it from long ago, she might not remember (or she might- Kate is becoming more of a mystery and I would like to see what makes some morphs retain their memory) but her heart treasures it.
Also curious, can a couple, both of them having undergone the unification, give birth to a child? Will it have shadow traits? While writing this I thought what if Kate(or who Emilyko met) and Emilyko are twins from such parents?
This happens when my mind goes into overdrive after I have seen spoilers but don't know what is being said apart from what can be clearly guessed from the pictures.
Wouldn't it be ironical if Emilyko was the one who took the identity of a shadow to go to the shadow house that is known to us to steal the identity of humans.
https://cubari.moe/read/gist/shadows_house/105-1/9/
https://cubari.moe/read/gist/shadows_house/105-1/16/
The more I reread I keep seeing the shadow as Kate. Or to the very least the one that Emilyko thought of when she wrote "Kate".
They are even wearing the same dress.