I had the option of leaving it and justifying it to myself by saying "that's what was in the reference photo," or making it better—either by painting it out altogether (Phoebe's suggestion, and it was a good one) or by substituting another hand. I was tempted to just paint it out, but my stubborn streak took over, and I decided I wasn't going to be conquered by that hand. It was a "duh!" moment when Pat said, "Um, can't you find a photo of a hand that will work with this pose? I've heard of editing parts that just don't look right...." I don't know why this didn't occur to me, on my third or fourth try, but it didn't.
I went on Google Images and searched for "hand on chest" and "hand on heart" and found three or four, but nothing with the exact angle of the original, so I got a little creative and substituted something entirely different. I put my painting into Photoshop Elements, then pasted in three different arms/hands at 60 percent opacity so I could see through to angle and line them up with what was there, and then used the one that worked the best without extending past her chest.
I painted out the old hand, painted in the portion of chest revealed by moving the hand, and waited for it all to dry. Then I drew in the new hand and arm, and painted them as they appeared, being careful about angles and positioning.
Ninety minutes later, Toni popped up on my Facebook feed and said "You can take a picture of yourself in that pose. It may be easier than finding the perfect reference photo." Visualize me slapping myself in the forehead. It's probably just as well, though; I have my father's giant ham hands and it probably would have looked even more like it didn't belong to Rose.
I can't claim to be a hand pro yet—this one still feels less expert than the surrounding portrait, and doesn't quite feel planted against her chest—but it's exponentially better than what was there before (you can see the old one if you scroll down to my previous post).
Thanks, everybody, for the encouragement (and all the suggestions that should have been obvious but somehow were not!).
"Rose with Roses #2"—with replacement hand! Pencil, acrylics, and stencil on thin birch board, 12x16 inches.