I have - for some reason - long wondered about this ever since reading Maid of the Abbey and have finally done something about it.
From Wikpedia we learn that the music was composed by Lisa lehmann - who was was born Elizabeth Nina Mary Frederika Lehmann in London. Her father was the German painter Rudolf Lehmann and her mother was Amelia (A.L.) Chambers, a music teacher, composer and arranger. Liza "grew up in an intellectual and artistic atmosphere" (Baker, 1992, p. 1030) and lived in Germany, France, and Italy in her early years. She studied singing in London with both Alberto Randegger and Jenny Lind, and her composition teachers included Hamish MacCunn in London, Niels Raunkilde in Rome, and Wilhelm Freudenberg in Wiesbaden.
On November 23, 1885, she made her singing début at a Monday Popular Concert at St James's Hall, and spent the next nine years performing many important concert engagements in England. She received encouragement from important European musicians such as Joseph Joachim and Clara Schumann.
She retired from the stage after a final concert at St James's Hall on 14 July 1894, and married the composer and painter Herbert Bedford. The couple's grandsons include conductor Steuart Bedford and composer David Bedford. For the rest of her life she concentrated on composing music. She completed one of her best known works two years later, in 1896, the song cycle for four voices and piano titled In a Persian Garden, settings of selected quatrains from Edward FitzGerald’s version of the Rubāiyāt of Omar Khayyām.
A full version (of the score) is available to download or view online from:
A full list of the songs is available below - I crashed the page several times trying to upload them neatly - and I can't store them as an attachment so you'll have to forgive the length of this page! But at least this will give you an idea of the songs Maid might have been practising, with Lindy eagerly listening in.