Penny Birch 
Taste of Amber [EPUB ebook] 

Expelled from school for spanking a head mistress, Amber Oakley finds herself in disgrace and is sent to work on a farm. Introduced to the strange delights of the world of pony-girls, Amber soon decides that she wants to be a pony-girl mistress. Unfortunately, others would like to see her at the other end of the reins, and when she loses a bet she’s been groaded into by Morris Rathwell, a property developer who sees himself as the king of carting, she finds herself in a very difference role from the one she’d anticipated. Worse still, she finds the role more enjoyable that she ever would have imagined. Can she ever hope to fulfill her ambition?