What book(s) are you currently reading?

A book about a girl who became a successful jockey winning every competition but as she grew up and gained weight, she couldn't compete in lightweight category anymore so she had to start training for horse jumping and totally messed it up because she wanted to win her first race. The horse broke his leg and had to be shot. She quit, ran away from that place and became a postwoman.

The author is Sieglinde Dick.