To find the Injured Spouse section in Turbo Tax, click on Federal Taxes (on the top menu bar) and then Other Tax Situations.  When the page opens, scroll down to the bottom and select the very last item, Miscellaneous Tax Forms.  When the list of miscellaneous forms opens up, look for "Report an injured or innocent spouse claim".  As you work through the form be sure you only answer the Injured Spouse questions (not the Innocent Spouse questions). 
Note:  You will need to click through several pages of Innocent Spouse questions before you get to the Injured Spouse section. 

If you are filing the Injured Spouse Form on its own (after e-filing your return), you will mail it to the IRS location for your state.  Include a copy of all W-2 forms and any 1099 forms showing federal tax withholding, for both spouses.  You can find the mailing address for your location using this link (use the 'not including a payment' address):   IRS Mailing Addresses for Injured Spouse Form

The IRS advises that you should allow an additional eleven weeks to process your return, leading to similar delays in any refund you are due.