If it was a verbal agreement only, you don’t have much of a legal stance. You can ask for the repayment, but she doesn’t have to pay up.
Long story short----wife left in 2005. It wasn’t in our divorce agreement, but we agreed that while I paid the insurance on our 3 boys, she would pay the co-pay when they went to the doctor and we would split the rest that insurance didn’t pay. So far this year we’ve incurred over $2000.00 that insurance didn’t pay. This started in January. So far she’s paid me $70.00 on it. Is there anything I can do to get the rest of the money from her? She has remarried and her husband is spending money left and right, but she tells my boys that she doesn’t have any money. Please help me out on this one…