Until now, almost good but there are some problems. See the below image. This is a part of her hair. We can see some background blue color in her brown hair.
This is because the selection is not perfect. Choose the layer mask of the model’s layer and click and push Alt key at the same time. We can see the black and white image of the layer mask. Black means no information and White means the information.Black part has no information, so we can see the background from here.