That reminded me of my older cat (I say older, I had to have her put down in 2006).
When I first got her, she was shy, timid, and always was so, but boy would she defend my kitten. When I got a kitten (as a pet for my dog), she took her in as her own, this little tiny kitten (who's now 6). Around the time the kitten was 6 months old, the older cat developed an eye problem (her retina ruptured) and ultimately became my one eyed cat (in addition to my three legged dog). for two weeks, Creamy had to wear an elizabethian collar was couldn't groom her face (she was a persian too). and every day, Faline would groom her. I wish I'd gotten a picture of Faline who at one point had one eye closed as if winking, and the other eye wide open, imitating her adopted mom.