Gilly's backstory

I have a theory for the backstory of Gilly, although I have almost no evidence to back it up with - I believe Gilly to be the daughter of Cornifer and Iselda.

The only piece of "evidence" I have is this line of dialogue when you meet her next to Karmelita's statue:

"Upon the last wish of my father, I've taken up the study of these wild caves."

For some reason, when I saw this yesterday on a new playthrough slot, my mind immediately went to Cornifer. Studying wild caves and exploring/documenting life there seems like something that Cornifer would very much do. Also, the tone of her dialogue, her overall vibe, and her chill-pacifist nature reminded me of Cornifer as well. Now, the argument against this theory is quite obvious, Gilly doesn't really resemble neither Cornifer nor Iselda, but still...something about it bugs me a bit. What do you think?