I worry that my early dolls, especially Hiro and Gavreau, are turning yellow too, but like you, I don't love them any less. And I will have to keep photographing them anyway, because I'm not going to write them out of my stories (well, when I get back into writing for them, that is)! They seem to still photograph beautifully for me.
As you mentioned, we all have to deal with age, human or resin. I am happy to hear you don't love her any less, because she is perfect for you.
Giant hugs to you,