Jonas taught piano at the Academy as early as 1838; following her graduation in 1841 she was hired by the Academy as a professor of piano and harmony - one of the first female professors at the Academy. She taught classes there until 1850. After her retirement she performed only in private, describing herself in 1854 as having been in ill health for several years. She actually survived many more years, dying in 1877, at which time she was living in St. John's Wood in London with her sister Emily.
Images
The engraving above is by lithographer Maxim Gauci. A portrait of Jonas was exhibited at the Exhibition of the Royal Academy in 1838 by miniaturist Mary Mulready Leckie.