I am "La Ana". (The Ana).

There is also El Curro, La Mai, La Concha, La Chiqui, and so on. I suspect this is a flamenco or gitano thing, (maybe even just a Vargas family thing).

Rafael is "niño" and Concha "niña", to each other. (boy, girl - general word for "child" but with gender).

But pretty much in any normal place, Spanish people call each other "hija", "hijo" (literally daughter, son). You don't even have to know the person for them to call you that, nor do you have to be remotely young.

"Tio" and "tia" (uncle, aunt) have dual meanings as "guy" (and whatever the feminine of guy is - we don't have one). It is used in a bit more of a casual/slang way than "guy". Kind of like "chick" and "dude".

Common terms of endearment are "corazon mio" (my heart), "mi vida" (my life), "mi alma" (my soul). Older people will call younger people by these terms, or even just anybody might call each other these, though possibly not men and other men.

I still haven't sorted out whether I should be calling Concha and Rafael "tu" or "Usted", and am erring on the casual side, which might not be good. I don't know.