Equine assisted therapy?

Monty Roberts, aka The Horse Whisperer uses horses in his work with veterans who have been traumatised in war zones. Monty doesn't believe in post traumatic stress disorder, he's had good results.
There are a number of accredited, qualified psychotherapists who use horses or dogs in their work with people who have mental health issues. Again, with positive results. I share your reservations Azie about the woman you met. The therapists I know had many years experience in working with people before beginning to train in using animals in their work.

My experience was that dogs and horses were a real aid in working with children.

I was a volunteer with Riding for the Disabled for many years and I have seen first hand how therapeutic it can be. The warmth of the horse combined with the rhythmic movement has soothed many a distressed child. The horses are specially chosen by qualified riding instructors and thoroughly tested under all conditions. There is always one person leading and one walking along side incase of any unexpected happenings. Insurance of course is in place and a qualified first aider present. This person offering rides on her horse for £120 and hour sounds as though she is out to make money. Any reputable riding school would be able to offer the same facility for a heck of a lot less.

There have been reports of very good results using horses as therapy. Partly perhaps because, although large, horses are naturally wary and vulnerable themselves. I would want to know that the person in charge had some sort of qualifications and was working with other professionals. Not just touting for custom from door to door.

I would definitely back off. If you just want to ride find a good local stables.

I suppose there are some therapeutic advantages to contact with animals but it sounds like a way to make lots of money out of vulnerable people to me, why an expensive horse when a cat or dog might do the same job.