1. Yes. CFR 1.401(a)(9)-5 A-4(a) says simply that the year-of-death RMD must be distributed to "a beneficiary." There is no requirement that the beneficiaries share equally in completing the year-of-death RMD. https://www.law.cornell.edu/cfr/text/26/1.401(a)(9)-5
2. Assuming that Mother was the participant of all three IRAs (none was an inherited IRA maintained for the benefit of Mother as beneficiary), Yes. Because all three IRAs were received from the same decedent and have the same RMD requirement, the RMD for each IRA can be aggregated with the others and the total taken from just one of the inherited IRAs. These inherited IRAs can also be combined into a single inherited IRA by trustee-to-trustee transfer, but not by distribution and rollover.
