I bought a copy of the book " The Scent of Roses" soon after it was published and have treasured it ever since. Here is a brief synopsis of the liner notes
In the 1950's Mary found fame and fortune as a harpist and singer
She met and married an american poet and Rhodes scholar Richard Selig
15 months after the marriage Richard was dead, struck down by cancer
Mary then joined a Benedictine monastery of Stanbrook.
After 12 years in Stanbrook she left to resume her musical career
she was very successful

I don't know where or what she is doing today, This book is a must for anybody who admired Mary O'Hara and her music. It was published by Michael Joseph Limited, 44 bedford Square, London, WC1. in October 1980.