My wife's 1099R was added to mine upon her death in May .Since her IRA was added before

I am assuming you have two 1099-Rs that show different names but contain the same distribution. You need to contact the issuer and have them correct the forms with the IRS and you. They should issue forms marked "corrected".

If they refuse, you can subtract the 1099-R under other income by entering a negative amount and the description 1099-R wrongfully issued or some such. Expect a letter from the IRS and you will need to be able to show a paper trail.

To enter:

1. You would go to personal income, 
2. scroll to the bottom to misc income, 
3. start, 
4. scroll to the bottom again, 
5. other reportable income, 
6. start.
7. enter negative amount and description.

I am very sorry for your loss.

I suspect that your wife's IRA was moved to yours by distribution and rollover rather than by the more desirable nonreportable trustee-to-trustee transfer.  The Form 1099-R for that would have code 4 in box 7 and the IRA/SEP/SIMPLE box marked indicating a distribution from an inherited IRA.  When entering such a Form 1099-R you would need to indicate that you are the surviving spouse and that you moved the money to another retirement account and indicate the amount rolled over.  TurboTax will include this amount on Form 1040 line 4a but exclude it from the taxable amount amount on line 4b.  TurboTax will also include the word ROLLOVER next to the line.  This is considered to be nontaxable income and has no effect on your tax return other than documenting the fact that you rolled the distribution over.