Loan to a minor

[LanceKS]

My 17 year old daughter is a model in NYC. I loaned (agreed in writing) her $21,000 (at the start of the year) to get her started. It was understood that she would do her best to pay me back by the end of the year. She now earns enough to repay me 2 grand a month but spends the money instead. My daughter will turn 18 on December 4. Does the law still recognize her debt obligation after she turns 18, in view of the fact that she was loaned the money as a minor? Is it more advantageous for me to set up a legally forced repayment plan (wage garnishment) while she's still a minor or after she turns 18?