Task: Question Answering
Input (English): Passage: Florence Fuller was born in Port Elizabeth, South Africa, in 1867, a daughter of Louisa and John Hobson Fuller. She had several siblings, including sisters Amy and Christie, both of whom subsequently became singers.
The family migrated to Australia when Florence was a child. She worked as a governess while undertaking studies in art, and first took classes at the National Gallery of Victoria Art School in 1883, then again for a further term of study in 1888. During this period she was a student of Jane Sutherland, referred to in the Australian Dictionary of Biography as "the leading female artist in the group of Melbourne painters who broke with the nineteenth-century tradition of studio art by sketching and painting directly from nature".Fuller's uncle was Robert Hawker Dowling, a painter of orientalist and Aboriginal subjects, as well as portraits and miniatures. British-born, he had grown up in Tasmania and made a living there as a portraitist, before returning to his native England at age thirty. For the next two decades, his works were frequently hung at the Royal Academy. He returned to Australia in 1885, and Fuller became his pupil. In that year, aged eighteen, Fuller received a commission from Ann Fraser Bon, philanthropist and supporter of Victoria's Aboriginal people. The commission was for Barak–last chief of the Yarra Yarra Tribe of Aborigines, a formal oil on canvas portrait of the Indigenous Australian leader, William Barak. Ultimately, that painting was acquired by the State Library of Victoria. Although the painting is an important work regularly used to illustrate this significant figure in Australia's history, interpretations of Fuller's portrait are mixed:
one critic noted the painting's objectivity and avoidance of romanticising Aboriginal people, while another concluded that "Fuller is painting an ideal rather than a person".In 1886, Dowling returned to his native England. Giving up her work as a governess, Fuller began to paint full-time, and had opened her own studio before she had turned twenty. Dowling had intended to return to Australia and had left behind an incomplete portrait of the Victorian governor's wife, Lady Loch. He died, however, not long after arriving in England; Fuller then completed Dowling's commission. Lady Loch became her patron. Other early portraits followed: two pictures of homeless children, entitled Weary (inspired by Henry Wadsworth Longfellow's poem on child labour "Weariness") and Desolate, in 1888; and Gently Reproachful circa 1889. Weary was acquired by the Art Gallery of New South Wales in 2015. The gallery's curator of Australian art described the depiction of billboard posters in the painting as giving it a "sense of gritty realism that was arguably unprecedented in Australian art."Also in 1889, Fuller was awarded a prize by the Victorian Artists Society for best portrait by an artist under twenty-five. 
Question: What is the last name of the person whose two sisters became singers?
Output (English): Fuller.