Hi @Scottydeez ,
Under the new rules, there is no Required Minimum Distribution on an inherited IRA, however you must withdraw all of it within 10 years from inheriting the IRA. If you inherited a large amount, you could spread it out over the 10 years.
If she did not take her RMD for that year from a traditional IRA before she died, the RMD must be calculated and distributed to the beneficiaries, who pay the income tax, before the remaining balance can be divided. This is one of the duties of her executor, and her broker will certainly help.
Here is a helpful link with more information:
Retirement Topics-Required Minimum Distributions (RMD)