Just caught up with this Mgm, sorry to hear you are having such problems, but good to hear things are looking positive.
Have you tried her with chopped alfalfa? Easy to eat and apparently very good for them, mine love a handful or so, they'll eat that when they wont eat hay.
BTW, I don't think 10 is old, my oldest is 10, she's kidded this year, I'd decided it would be her last year, she fooled me with triplets. I am giving tnem extra milk from the others, but the mum is doing OK.