Dear brothe/sister
:salam2:
I tried looking for the exact answer for your question but by far, this is the closes I can get to the answer to your question.
http://www.islamweb.net/ver2/Fatwa/ShowFatwa.php?lang=E&Id=91419&Option=FatwaId
Question:
What is the ruling of women riding horses in public places?
Answer:
Riding horses is one of the greatest reasons of unveiling some parts of one’s body, like legs and arms, and it is also a reason of wearing some tight clothes which shape the body, while a woman is ordered to cover all her body and she is forbidden to appear in any form which could lead to temptation. Allaah Says (what means): {… and to wrap [a portion of] their head covers over their chests and not expose their adornment [i.e. beauty] except to their husbands, their fathers, their husbands fathers, their sons, their husbands’ sons,…}{Quran 24:31]. Therefore, it is absolutely not permissible for women to ride horses in public places.
Allaah Knows best.
Sister Nur