Major Robert John Waller was a professional soldier. His daughter Maud posed to JW (Study of Maud Waller for 'Scherzo in Blue: The Blue Girl' (M.846) and Scherzo in Blue: The Blue Girl (YMSM 226)). His brother Pickford was a collector who owned many works by JW.[mfm says Maud was daughter of Charles Bullen Waller and Emma Piggott]
Kelly's London Postal Directory, London; UK census 1881, from http://www.familysearch.org (accessed 2004).