I find reverse glass paintings pretty magical feeling things, and love the luminosity of this small portrait, with the face of this woman in braids seeming absolutely as if glowing from within. Mid 19th c. continental European and I'd guess French in her red, white and blue. Clearly the painting was once in a frame, with a dark outline left on the glass--but I think all the better without it, so as to prop her somewhere with light coming through, which makes the brush strokes, especially on her hair, all the more apparent. (I have shot her head both ways to give a sense.)

6 1/8" x 4", overall good condition, with small loss to upper right corner of glass and some paint loss as evident.