On the subject of blind sheep, I'm not convinced they are happier in a flock, although that may depend on when and why they became blind. We had a blind lamb and she was very much a flock animal, using her hearing to stay in the middle of her pals. We have had several old ewes (up to 21 years) who get cataracts, so have lived a sighted life then become blind. Sometimes they are happiest in the flock with their relatives and offspring, or a friend who will look after them. We have a 17yo who went blind a couple of years ago. At first her best friend stayed with her, protected her, led her to food and water. Sadly the friend died last year and Elphie is now on her own, which she is perfectly happy with. The ewe flock is through the fence, but if they are in the paddock with her (she can't eat ALL that grass herself so it gets mob grazed every now and then), they shove her about and don't let her have her special rations (no teeth). At the moment she has the tupping group through the fence on one side and the unbred ewes on the other and has developed an interest in the tup. We know she wouldn't stand for him even if he jumps in so she can be lovesick for a bit if that appeals to her. She does listen to the rest of the flock and sometimes talks to them through the fence, she has hen friends in the pasture with her (we're in Scotland so no lockdown yet) and our pup loves to wash her ears. The only time she is unhappy is when it's very windy and she can't hear where she is, so she will go to sit it out in her shelter.
I would not think it would necessarily be good for your ewe [member=222091]Macey Grey[/member] to be sent to live in with a new flock. She would have no idea of her way round, she would know no-one in the flock, she would be shoved around by other animals so she would be miserable and stressed and she would not know the new human. I know the mantra is 'a sheep is a flock animal' and that is true almost all the time, but not necessarily for a blind sheep with other sheep she doesn't know. To introduce a single companion it would need to be on her home ground and they would need to be penned up together for a few hours first to get to know eachother. Should you find a mythical small flock who want to take on a blind sheep, then one animal from the new flock would need to be housed with your ewe for perhaps a week, so they became friends, before they went out with the whole flock. That might work but it very probably wouldn't. All in all you are best to keep going as you are.
For hay, as others have said, if she's hungry then she will eat good, sweet hay. She may not eat old, dusty hay. Offer her good hay ad lib ie there's always some untrampled hay available in the same place, under cover for her, don't cover it with other stuff, don't fill her with concentrates as she doesn't need to be fat, and she will eat her hay one day.