Funny thing is that the painting was not entitled "Whistler's Mother" by Whistler. He called it merely "Arrangement" but an explanatory addendum was added on first exhibition in 1872 at the 104th
Exhibition of the Royal Academy of Art which said "Portrait of the Artist's Mother." in London. People of the period objected to calling a portrait sitting with a person in it a still life "Arrangement" so the popular press critics, liking the painting, started calling it Whistler's "Mother", even though it was not his name for the painting and their popular name for it angered him. A further addendum to the "Arrangement of "in Grey and Black, No. 1" was added in later years because Whistler did a second painting named "Arrangement in Grey and Black, No. 2" and since there was no Whistler painting "Arrangement in Grey and Black, No. 1" the first had to be the Mother painting, the only similar painting done by Whistler.
Arrangement in Gray and Black, No. 2.
Two women actually sat for the "arrangement", his mother was the primary model whose face is portrayed, and a young girl, Helena Amelia Lindgren, from next door who substituted for the his mother when she got tired of sitting in the same pose for hours.
From what we were told in a docent talk with the exhibit, Whistler was in a constant battle with his critics; that included the *naming* of this painting. Whistler often envisioned and entitled his works with the abstract language of music, calling them symphonies, compositions, harmonies, nocturnes, arrangements, and such.
This is supposed to be his model/mistress...
Symphony in White No. 1 - The White Girl[1862]