i like creative challenges like this, too, sometimes. if you make it a less formal lesson than the norm - she won't be stressed and neither will you. older people forget things more - so just expect that you'll do some repetition (unless she's really sharp). but, it's probably a good idea to involve her a lot in dialogue. sometimes they're after that more than the lesson at that age.
wonder if you could make note rhythm flashcards using a stencil technique so she could feel the different types of note rhythms.
also, you could make a patchwork pillow with four squares (whole note , half, quarter, eighth) in which the notes are stuffed with cotton. blind people seem to like having tangible things to feel. it's comforting. you could move on from there to another pillow with quarter, two eighth, and four sixteenth notes on another.
this is really bizarre idea - but what if she read music with her feet? using bare feet - you could make a system of note reading that she scans with her feet. have to think some more on that one. left foot for bass clef and right foot for treble.