State if an enforceable contract has been made or not. Explain your reasoning.?

[ricancutie4u]

I have a daughter who is 18 years old, and she has just graduated from high school and does not desire to attend college. I promise her $5000 if she will attend an accredited college and obtain a four year degree within the next five years. She accepts and starts college. Four years later she graduates from the University. I refuse to pay her the $5000. Who wins and why?