I did the Princess marry route, married her ... and Aire came with her to the mansion.
I then went back to Duncan and the option "I want the Elf Girl" is there ... clicked it and the dialogue seemed to be me retrieving Aire from the jail. After the dialogue, everything is normal (no duplicate Aire's or anything) ... but maybe either this dialogue option needs a check added, or Aire wasn't supposed to follow the Princess upon marriage.
For the record, I had done the Griffin quest before I noticed Duncan had the dialogue option.
There doesn't seem to be any negatives at all with this. Just an interesting thing. I have attached the save file I made before clicking the dialogue option. I am using the AIO Portrait Pack from the original Strive if that matters for loading it.
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