TurboTax has no information about your back child support or whether there is an order in place to seize your refund to pay that child support. You can check here:
You can contact the IRS Treasury Offset Program Call Center at 1-800-304-3107 to ask if they have an offset for you on file. TurboTax would not have that information.
https://turbotax.intuit.com/tax-tips/tax-payments/who-can-garnish-an-income-tax-refund/L7cPPzDyc
If the IRS offsets your refund for the child support you owe, then you will receive a letter of explanation from the IRS.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**