TurboTax never knows about any debts or child support, back taxes, etc that you owe. The IRS does not provide that information to TurboTax. You can check to see if there is anything listed with the Bureau of Fiscal Services.
Reduced Refund https://www.irs.gov/taxtopics/tc203
NOTE: 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.
If the IRS filed a federal tax lien against your property they would have sent you a Notice of Federal Tax Lien Filing. You can find out if there is a federal tax lien against your property by calling the IRS Centralized Lien Operation at 800-913-6050.
A federal tax lien is not just an amount that you owe. It's a legal claim against your property that the IRS files if they have billed you for tax that you owe and you did not pay by the deadline that the IRS set. You would have to have ignored several IRS notices before they would impose a lien.
Go to the following link on the IRS web site for more information about federal tax liens.