John, Paul, George and Ringo signed their monikers on a scrap of paper at a small gig in Whitchurch, Shropshire, on 19 January 1963.
The 16-year-old who got the autographs had gone along because she knew other singers performing that night.
The Wrexham woman left the piece of paper in a cupboard for decades. It is expected to sell for up to £3,000.
“Because there was so few people there, it was quite relaxed and we got to chat to The Beatles and ask for autographs,” said the woman, 72, a retired secretary who does not want to be named.
“I remember John Lennon plonking away on the piano after the gig. “I asked Paul McCartney for his autograph and, as he wrote it, he said out loud, ‘to the most beautiful girl in the world, with all my love and affection’. “He was only joking but it’s been my claim to fame ever since.”
She said she put the autographs in a cupboard, as she was worried the signatures would fade if left in the light.
The framed item is set to go into Hansons Auctioneers’ Music Memorabilia sale next month with an estimate of £2,000-£3,000.
The Shropshire gig came just over a week after the Fab Four released their first big hit, the single Please Please Me.