usually this is considered to be a gift between the parties. You are going to have to show that this was an actual loan whose intent was to have it repaid.
This may require a separate civil action.
Call me with any questions.
Based only upon the small amount of information you provided, I think your chances of recovering the funds you borrowed to help your step-daughter are slim. Of course, getting more detailed info about your case would be helpful in order to provide actual advice.
You can still proceed with your child support contempt and modification case. Seems to me that this issue is completely separate from the money you gave to your step-daughter.
Good luck with your case.