Real person identified by relationship? No.
Non-famous real person female? No! *applause*
(I'm reasonably confident, by the way, that INJ will know/remember the answer, and I think most Morniversers of my age or older will also know it. I'm less sure about Young Master Projoy and his contemporaries -- they may need to use the google -- although I think there is a good chance that he (they) would at least know another song by the group.)

I can think of 2 60's songs with that title. The one by a group would be The New Vaudeville Band IIRC (not googled)

INJ has it! Rosie by the New Vaudeville Band is the answer on the card. The timeless lyrics, for those of you who have forgotten, began
There's a pub in town called the Rose and Crown
And one day I met Rosie there.
(dadada)
She served my drink with a knowing wink
I knew that I would get somewhere
(dadada)
I heard her whisper she was mine
So we left before closing time

Rosie was on the B-side of Finchley Central. Timeless lyrics:
Finchley Central is two and sixpence from Golders Green on the Northern Line
And on the platform, by the kiosk, that's where you said you'd be mine
There we made a date
For hours I waited
But I'm blowed, you never showed.

However, the NVB were most famous for Winchester Cathedral, a top ten hit in the UK, and number one in the US. I won't bother to reproduce the timeless lyrics. Part of my reason for choosing this answer was the discussion of music over at mcios, where INJ observed that a lot of that 60s music we thought was so great doesn't actually hold up all that well. And yet, and yet...

The link to Software's Caroline guess was through Neil Diamond (Sweet Caroline and Cracklin' Rosie). I will leave it to Rosie himself to tell us if he was a (a) an adult and (b) a great beauty in 1967.

*takes baton made of polyvinylchloride, drills very narrow hole through the center along its entire length, compresses the ends of the cylinder until it is a flat disc of about 17.8 cm diameter, and gives it to INJ*

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And again Projoy asks the key question and someone else does a Cavendish on him. I feel almost embarrassed (but not enough to give up my turn).

OK, this one is VEGETABLE