Inheritance for Minors

Dear Len & Rosie,

I am the custodian for a $55,000 UTMA account for my 16-year-old daughter that was given to her by her now-deceased grandparents. My daughter is supposed to use it to pay for her education. But at this point in time, she wants to buy a Camero and move into an apartment on her own. And no doubt party till the cows come home.

I want to move as much of this money into an account that she cannot access when she turns 18. I've done some research and it appears that I can use the money for expenses such as education, camp, her car, medical expenses, and even general living expenses. My plan is to keep about $10,000 to reimburse myself for the car I bought her and her medical bills, and to put the rest into a savings account in my name to distribute to her as I feel appropriate.

Are there any time limits on how far in the past I can retrieve funds for reimbursement and stay within legal boundaries of the use of this fund?