This painting, kindly sent to me by Ruth Marler, is by the Russian artist Marie Bashkirtseff (1858-1884). You can see from those dates that she was only 25 when she died, from tuberculosis. According to Wikipedia,
From the age of 13, Bashkirtseff kept a journal, and it is for this that she is most famous. Her personal account of the struggles of women artists is documented in her published journals, which are a revealing story of the bourgeoisie. Titled I Am the Most Interesting Book of All, her popular diary is still in print today.
I'm sorry to say I'd never heard of her, but she sounds like a fascinating woman. I'm wondering if the painting above might be a self-portrait, as I think I see a resemblance to her photo (from Wikipedia).