Question on using horse for Para-Dressage

My son’s pony club is hosting a dressage show, and they are planning on adding a class for para-riders, from the local Therapeutic riding barn. One of the instructor ask me if they could use my children’s horse for one of the riders.

I said sure no problem. The mare is a great babysitter, works to the level of the rider, and is regularly ridden by both my 10 yr old and 6 yr old. Has done lead line and is very safe for the young one. She is a retired eventer, so is used to the dressage ring, and LOVES shows:D

Having never done anything like this with my horses, I was wondering if there is anything I could do with the horse to get her use to having a rider with a disability on her? Or should she be generally ok after dealing with two kids and their antics?

I would ask the instructor if the had a certain rider in mind and what the riders disability is. Therapeutic programs cover a lot of disabilities. I would ask to see if your horse needs to get used to anything.
I use my own horse that I have had for 15 years. She would never be a good therapeutic horse. However I am just losing my eyesight so compared to a lot of riders I have it easy. Just saying if the instructor thought your horse was a good canidate, he probably is. No harm asking though.