Cool story! I like "As she turned on the lights, all the horses nickered..." I can nearly see the horses' bright eyes and smell the hay. You could spruce the first sentences up a little bit to make them even stronger. A little detail goes a long way - try something like "Abby woke up on Tuesday morning when the sun was just peeking over the eastern hills..." Just as an example - I'm sure you can come up with something much better. All in all, awesome story! I can't wait to see what happens to Fireball and who whipped him!
Unicorn
writer of "El Cheapo" parts 1-7 www.horsecrazygirls.com/el-cheapo-part-i.html