I can't remember after 35 years the music he sang, but now I remember it was a song and not an opera aria. I had assumed the two titles must be opera and aria titles. Could they actually be two different songs? Rubini did mislabel things at times, perhaps omitting a different composer for the second title.
I don't think there is an English idiom using fair hair in this way. (There is one with "Blue-Eyed Boy"). And I'm sure an English translator would not use an idiom to translate a Russian title not much known in the West. So I think, whatever the Russian form is, it means 'Blond Girl' exactly as you say.
But I could not find "Fair-Haired Maiden". May be I incorrectly understand it as "Blond Girl" ? Can it be understood as "Well Behaved Maiden" or "Favourite Maiden" using analogy with "Fair-Haired Boy"?
This is the one that I remember was recorded in a hotel room.
Dargomizhskii The Kiss. The Fair-Haired Maiden. It is on Rubini GV15, Famous Russian Singers Vol 1, LP issued about 1973.
The original record came from the Stuart-Liff collection.
It is not the other Gramophone recording which was a song by Cui.
