I am assuming that you are referring to the integration of the painting into the frame and wall image.
I think the only things missing from this are the bounce light from the frame and the AO/shadow from the frame to the painting plane. Very minor touches and I would bet that you just aren't up to that part of the process yet.
There might also be an image compression difference between the painting and the rest of the image, that might be texturing on the frame that I am seeing but it looks a bit more like compression noise.
Now if you are referring to the painting itself, the grey highlight hairs on the far sides seems a bit flat considering the angle of her head and the placement of the hair, it only stands out because of the attention paid to the depth on her torso and arms, a very minor thing. That is the only thing that might merit change in the painting.
Looks great.