"I think I would probably feel something from you, even if I had no idea what it meant. I could be mistaken, but since you don't believe you have such a thing either," shrug "it seems simplest to believe I don't perceive anything because there's nothing there. In that case, anyway. Honestly--to my senses you don't seem to be different from a human at all. Aside from the obvious biological differences, of course."
Isabella waggles a wing. "They are generally considered sufficiently obvious to make identification trivial."
"The metaphysical specialness of angels is often exaggerated at home, but anyone can tell it doesn't do very much if it exists at all."
"...My God isn't cut off from this place when I have the door open. It...is my strong impression, via I-am-a-living-conduit-of-his-will, that he wouldn't...interact with you, without your consent. If looking at your world isn't possible due to entirely reasonable practical concerns, could He get a look at you?"
And then it is over, and she is merely a tall woman.
"Well," she says. "I know what's going wrong with your kids, anyway. Not that I'm sure how to explain it to someone who probably doesn't have a grasp on Mendelian inheritance. Um...angels have a thing in their bloodlines, and mortals don't, and if you're an angel you can pass on the thing to your kids or not, and a Lucifer has the thing from both parents, and that's too much."
"That makes sense. Although once two angels were given dispensation to marry. They had mostly angel children, all healthy, and one mortal."
"If someone with a Lucifer's blood were somehow rendered healthy without changing their blood, and they grew up and had children with a mortal, they would have naturally healthy children all of whom were angels," she adds. "Not that that's particularly relevant, but just as an addendum on how that sort of thing works. I suppose in the instance you refer too...if I had to guess, there would be something about the angel woman's body that would make her miscarry a lucifer before it was old enough for the pregnancy to be noticed."
"And...I think I have an idea of why your world has some of the terms it does. It looks like the people who first came to your world were the descendants of people who had lived on an Earth much like ours, and much of your culture based on our mythologies. 'Lucifer' as 'bad angel'...makes sense in that context."
"There is a folktale about the origin of the word, but it's unclear how true it may be."
"Then yes, of course under that definition we qualify - except that you can maintain a population of all mortals and no angels perfectly well, but perhaps that doesn't matter?"