I think you are referring to my Aunty Peggy Kavanagh, as I do remember my mother saying she had been Mrs Johnson-Barrett before her divorce. I am sorry to have to tell you that my dear Aunty Peggy died on May 16, 2007, and was buried under the name Margaret Hudson, Michael Hudson (my Uncle Mick, whom I also loved very much) was her last husband, and he died some years earlier. Aunty Peggy and Uncle Mick moved to Manchester in the UK when I was about 18, and I emigrated to Australia in 1969 and sadly, never saw them again. When I was a baby, Aunty Peggy lived in Cobh, County Cork, with her mother Bridget and father Patrick. I was born there. My father was named Patrick after my grandfather.
If this is the Peggy you are looking for, I am sorry to be the bearer of sad news.