The short answer is to use a layer mask, selections and maybe the gradient tool.
Let's say you have a bg layer of your mother. Duplicate it. (Or, change the background layer to layer O by clicking it.)
Either way, next put a new empty layer underneath the duplicated layer of your Mom and fill it with white. Could be another colour, doesn't matter, whatever you like.
Return to the layer of your Mom.
Next, make some kind of oval or round selection around the part of your Mom that you like, and then feather the selection by some very large amount, like somewhere between 40-70, for example.
Then go to the bottom of the layers pallette and click on the button that will add a layer mask to this layer. If you like what you see, good. If not, there's no harm in starting over with the layer mask, the selection, and the feathering, as nothing's been destroyed.
Or, and this is the method I prefer, put the layer of white above the layer of your Mom. Add a layer mask to it. Then run the radial gradient around this white layer, making sure you have the gradients' setting to fade away to transparent. What'll happen is parts of the white layer will disappear in a nice, gentle way, revealing what's underneath.
There's other ways, but these two do a nice job.