If the inherited IRA was rolled into your mom's own IRA and the 1099-R distribution code is 7 then it is no longer an inherited IRA - it is her IRA.
If the box 1 and box 2a amounts are the same and the box 2b (not determined) is checked then, assuming that the IRA/SEP/SIMPLE box is checked, it should all be taxable on the 1040 line 4b.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
