By any chance did she take more than required from her IRA?
Did she elect to treat his IRA as her own?
If yes to both of these, she may be able to minimize the hit on the missed RMDs as the total of both IRAs is used to calculate the RMD for her for each year.
For example, if her RMD was 10K, and his was 10K, but she took 15K each year (5K more than her RMD) she would only be required to pick up 5K for the year.
Not sure if this helps, but something to look at.
Tom
Longview, TX