Maedhros: What's this?
Maglor: it's two babies I found in the trash!
Maedhros: ...well put them back
Tbh Elwing's fate sounds a whole lot like smt you would tell a kid when somebody died, along the lines of "your cat moved to a nice farm upstate". So just imagine that at some point the Kidnap fam had this conversation:
Maglor: and then your mother turned into a bird and flew away
E&E: you know, we're not children anymore, we know that's not true
Maglor: no I'm not lying that actually happened
E&E: yeah right, let me guess, she also found dad and they're very happy and not at all dead
Maglor: I... yes, kinda???
Maglor: I'm not the step-dad, I'm the dad that stepped up!
Maedhros: We literally kidnapped these kids and ransacked their city
Maglor: there was a kid napping at sirion!
Maedhros: what?
Maglor: yeah but it's ok, he's awake now
Maedhros:
Maglor: on an unrelated note, have you ever wanted to be a father?