A Change of Heart [delayed]

They say when in an argument or disagreement you should put yourself in the other person's shoes. But how do you deal with life when someone else's heart is put in you?

A fourteen year old girl living in Michigan in the year 2037 thought she was living her last days, as she had a rare cancer (heart cancer) that's cure was undiscovered and she had limited time. When her time runs out, she finds herself waking up in a new life, one where she is a new person, without cancer but there is only one thing. It isn't her.

The doctor's recently discovered that they could transplant hearts those who are dying due to heart failure and replace them with the new heart. But what they didn't know was what a heart carries.