Cab Calloway did a song called "Daddy Dear" with his daughter Lael.    It's a bit schmaltzy but definitely designed for a duo like yours.

Depending on how old your daughter is, I think the two of you might be able to pull off the Makeba-Belafonte duet beautifully.   The duet is between a man (either the paramour or just one of those "society" types who calls everyone "darling") and a woman whose husband is home ill.   It's a comedy "routine" song.

As you said, what else is poetic license for?   Or "role playing," for that matter.

If you sing "Edward," nobody's gonna think one of you is really guilty of fratricide. LOL