The disclaimer: I am not an expert on saddle fit. Does she react to your hand when you gently palpate her back?
Horses (like people) have varying degrees of ticklishness, but usually the endurance horses we see with sore backs will flinch to touch. Don't dig your fingertips in. Most horses will react to that, sore or not. Just run your flat hand over the back with a small ( I know that's a relative term) amount of pressure. Nancy
