In 1978 she sang Rameau's Phèdre (Hippolyte et Aricie) at the English Bach Festival at London's Royal Opera House, Covent Garden.
In 1979 she appeared as Monteverdi's Nero (L'incoronazione di Poppea) with De Nederlandse Opera in Amsterdam.
Also in 1979 she was featured as the contralto soloist in Christopher Hogwood's landmark recording of Handel's Messiah, with the Academy of Ancient Music.
In 1981 Watkinson made her La Scala debut in the title role of Ariodante and sang Rossini's Rosina (Il barbiere di Siviglia) in Stuttgart.
She was a soloist in Bach's St. John Passion at Gloucester Cathedral in a performance shown on BBC TV on Good Friday in 1989.