Inherited IRA for minor form 1099-R

Hello! I was wondering if anyone dealt with this issue - my child has an inherited IRA.  We pulled out 2500 last year and received 1099-R.  When I input 1099-R into Turbo Tax (I have Premier - home and business), it calculates a tax of 121.  Income is listed as 2500 and standard deduction as 1300 (calculated by TurboTax).  What's leftover is 1200 with 10% tax.  Am I doing something wrong?  I thought that 2500 is not taxed.  Thank you!