answer:How much time is she spending on the horse each day? Is the riding intense, or is she starting out slow and still having this much trouble? If someone with no riding experience started spending time each day, they’d have different levels of soreness just depending on how long they were on the horse and how rough the riding was. When I was a kid, I took weekly riding lessons for years. There were times when my legs were a little sore, but I don’t remember my butt hurting. I certainly didn’t get any bruises, even once I progressed to things like trotting (very bumpy) or cantering. A couple of months ago, I went on an hour-long walking trail ride with my daughter. Years ago that wouldn’t have phased me, but by the end of it my knees were starting to ache. Apparently being on a horse for a while at age 35 is quite different from age 13. :(