Climbing Competition

Irelynn is a ten year old girl who loves climbing trees, and has a fear of pencils.  She has a best friend named Shannon, she loves to draw, but has a fear of heights.  They're not a great match, but have known each other since they were toddlers.
At their school, there is a competition.  A climbing competition, to see who's the best at climbing one of the most advanced trees to climb in the country, in their home state, Nebraska.  Of course, Irelynn tries out for this competition.  But when she makes it to the finals, she falls from thirty feet in the air and breaks both of her legs, badly.  But in the middle of the night, in her wheelchair, she wheels herself  to the tree and climbs with only her arms, only making it fifteen feet before slipping and falling, only to meet what is closest to death.  
Irelynn has hurt her legs so badly that they have to be amputated, and it seems as if she will die soon.
Shannon visits Irelynn in the hospital often, and Irelynn tells Shannon to finish the competition for her, it's what she had dreamed to accomplish and it couldn't go this easily.
Shannon has to overcome her fear of heights so she can finish the competition for Irelynn.  Will she finish the competition without a scratch, or will she end up just like Irelynn?