I don't know if anyone will see this or even care, but it's not that odd (to me) for her to refer to him as "(insert child's name) dad". I feel like that is a rather common thing, to be referred to by name of the first child/son. You could say it's almost like a title. My parents are usually...
Wait... I'm confused. It made it sound like he brought her to her home and then found out she was nobility? Like... how did he know where she lived? Even if he for some reason already knew, as an Earl, the Castillo estate must have been decently sized. That already screams nobility or at least a...