Yes, you must indicate that it's an inherited Roth IRA.
If her Roth accounts have met the 5-year holding requirement because she made her first contribution to any Roth IRA for a tax year before 2014, all distributions you receive from this account are qualified distributions, entirely tax free. If her first contribution to a Roth IRA was for 2014 or later, distributions follow the ordering rules for nonqualified Roth IRA distributions, with taxable earnings coming out last.
If you did not received a distribution of substantially less then the full balance of the Roth IRA, it's likely that that you received a distribution allocable only to original contributions, tax free. But ideally you'll want to answer TurboTax's questions accurately.
