I've repaired dolls like this before too. You need to find a fabric of similar color to the face and make a new one, then applique it on and using fabric markers you can draw back in the facial features. Applique using small stitches up under the hairline so it doesn't show and on that drawn in chin line. You could even add a little stuffing around the chin and cheeks to give dimension so it looks like it should have been that way. Then take your own makeup blush and using a q tip put some blush on the cheeks. You can seal the face using a spray sealer by Krylon for fabric. It seems to be a daunting task, but it won't be that hard.