Senki to Yobareta Otoko, Ouke ni Ansatsu Saretara Musume wo Hiroi, Issho ni Slow Life wo Hajimeru - Chapter 23
Comments for chapter "Chapter 23"
There are uncountable Mangas where the MC collects harem girls..
But this might be the first one I have read where the MC runs an orphanage and collects daughters..
Wholesome… 
I was thinking, that somehow, Maria and this girl are clones.. Fabricated humans..
My guess is that she is Maria’s actual twin sister. She was just thrown out after being deemed useless by her mother (I’m still guessing is the witch lady) and the other sister was sent to Ordoll.
My guess is that Maria was sent for a reason but the other wasn’t supposed to survive. The fact that she’s here now might make problems for the witch (whatever her name was) in the future.
It’s mostly just a theory but I feel like it has strong standing.
She should be named Mercedes, to compliment her step-sister’s name, Maria.
It would be like the mexican telenovela, Maria Mercedes~
either Maria and Nys are twins, or my theory is they are the same person split apart with magic.