We had a blind Shetland ewe lamb a few years ago. Her mum was brilliant with her, and as yours has a pal it should work OK. Alice always loved running with the other lambs at mad time - she would put herself in the middle of the group so she would avoid running into anything, then charge around at top speed with them all. She did that with the following year's lambs too. After 3 years her dam suddenly died and she was alone, so we let her lamb, to a Soay tup. In spite of my fears, she lambed without a problem and her lamb Dove soon learned she had to bump her mum on the chest before going round to feed, so Alice would know it was her. Alice died the following year. We didn't breed her pure, nor did we breed from her dam again, in case the blindness was hereditary. Alice herself got around by listening and smelling and only occasionally bumped into a fence or similar. If Alice is anything to go by, yours will soon learn to stand up for herself. I would suggest though that when she first arrives you keep her in one small paddock with her pal for a while, before she has to face the flock and learn her new surroundings.