[member=200028]corserpaul[/member] Our oldest ewe was 20 and the oldest blind one died just before her 20th birthday. However, neither of them was deaf as well. We currently have a blind ewe who is only 16 (our sheep are very long-lived so this is quite a youngster still) and we are very aware that when it's very windy, which it is at the moment, she can't hear where her mates are. Mostly she guesses where they are and traipses around until she bumps into them. Once the wind drops she is perfectly fine with being blind. When elderly ewes have gone blind we make sure to teach them directions and a couple of warnings ('stop' and 'careful', as well as 'right' and 'left') - sheep are quick learners even when old.
Very sadly, I think your old lady will be stressed by being both blind and deaf. You are the one who knows her and will be able to tell when the time is right to let her go. We either shoot them ourselves, or get the knackerman to come and use his captive bolt, rather than sending them off somewhere which would cause her to be fearful. We pen up the ewe ready and give her food and water - when the lorry arrives, we give her treats so she is concentrating on food when the man does the deed. It is very sad with all animals which don't live as long as we do, so we have to say goodbye to them but if you do it well, and don't leave her to suffer, then you will have done the best you can by her. Make sure that if you delay it's not just for your benefit.