Sounds horrible, sorry.
She should be kissing your feat for offering to replace FOR NO EXTRA CHARGE. If I were you and she told me that she was unhappy, I would have said "goodbye".
I clicked the link and am looking at the photos, they're great, great composition, processing, lighting. You could touch up the face pretty easy in GIMP but I would never do that without the client wanting it, and obviously not for her+she didn't ask. She complained(rudely), not asked. Sorry that happened, these things happen. Keep on truckin' tho.
Also, next time I would throw in on the contract you make them sign when you make your agreement something along the lines of "Please do not bring your own camera's." Because, if they are taking their own photos, why on earth are they paying for your services? You could include that or something like that in your
investment page thing.