Pretty much. I always turn any selection into a new layer. I selected all of her with the lasso tool, bad arm included. Turned that selection into a new layer and erased the right arm. Then I selected (with lasso) the left arm and turned a copy of that into a new layer. Flip it, place it, do a little blend and good enough.
Gotcha. Thanks!
I almost always work in layers. Kind of a nice "safety net", plus you can do so much with them.