Alice Parker's Metamorphosis

Thirteen-year-old Alice Parker knows something isn't right; mysterious aches and pains, a craving for sugar that's out of control. Suddenly she is top of the class in every subject.
  
Baffled by what is happening to her and feeling at odds with the world, Alice can't take much more. Only when she collapses and experiences a life-changing transformation does she discover why she is different. But this new, incredible identity brings its own challenges, and Alice isn't convinced she can rise to them. She just wants to be normal!

The fact is she's anything but. . .