Be skeptical. However, it's not the first incidence of "internal decapitation" to be recorded. It DOES happen.
Slightly off topic, I'm interested in the technology to possibly decipher when patients are faking pain/inyuries because, whoo boy, the demand for opiates and/or permanent disability is skyrocketing. There are legit cases and many, many more suspicious cases.
My dad broke his neck in the same spot, and doctors also referred to it as the hangman's break. He lost the use of his arms and gradually has gotten back about 95% use (you wouldn't know he has any issues to look at him, but it is hard for him to lift his arms above a certain level, his fine motor skills can be iffy, etc). It's a very very scary thing, and she is certainly lucky not only to be mobile, but to be alive!
If this is a true story, (and I agree, it is after all the Daily Mail), maybe the orthopedic surgeons and therapists needed more business. One does have to wonder about the sanity of someone who would ride the same horse, nevermind any horse, who would throw her, then run around so panicked that she was afraid of being stomped. Nuff said.
"We, too, will be remembered not for victories or defeats in battle or in politics, but for our contribution to the human spirit." JFK