Horse Racing Mania

I bet you did not think that all these famous characters, such as charming Barbie or sweet Dora, were this crazy about horse riding and horse racing! Well, they are, and they're all determined to win this major horse racing championship here! Which one of them would you kike to lend a priceless helping hand to, clicking the indicated arrow keys and the space bar key whenever needed, for helping her/him speed race, while galloping, with the speed of light and jump over all the fences on the track?