Welcome to the forum! I have a blind horse and I would not consider any type of electric fencing for him. He uses his nose to feel things to get his bearings. For instance, he knows the general area of the water trough, but feels with is nose to find it. If he were to touch an electric fence any time he went for water, he would turn into a nervous wreck, maybe stop trying to drink altogether. We have 5 ft No Climb around ours, but that is pretty pricey. To have safe fencing, you are likely looking at a pretty hefty expense. Vinyl or rubber fencing would be good. Maybe you could run a single strand vinyl or rubber fence a couple feet on the inside of the electric so she will stop short of the electric fence? Or several strands of tape fencing that are not electrified. Most blind horses will not push through barriers.
I have heard of people putting a strip of gravel a couple feet wide so that if the footing changes the horse knows to stop, but it would still be expensive, and not something I would trust to work.
"Keep a leg on each side and your mind in the middle"