Money given to a beneficiary prior to death.

[way2passionate]

What is the name of your state (only U.S. law)? Idaho

My Father died recently and my Uncle, (the first executor/PR) made a huge issue about monies my father gave to my sister over the last few years. I am estimating that the amount given to my sister was in excess of 100,000.00. My dad did not make reference in his will for this to be paid back, he stated "sell all assets the kids don't want and divide it between the 3 siblings" (he wrote a holographic will 2 days prior to his suicide). This money was for a divorce secondary to an abuse issue with her 6 y/o son and her husband as well as money for tuition so she could finish her degree. My uncle thought my brother "got cheated" in the end financially and now, so does my brother. My Uncle has since been removed and we have a new Executor/PR. The current executor/PR told me that the accountant (the same accountant that my Uncle was using) told him that this money given to my sister is in question and "may affect ______(my sister)". He didn't clarify what he meant by that but the more I think about it, I don't understand how it could affect her...It was money my Dad gave to my sister to help her out of a bad situation and I know she would have paid him back at some point if he was still alive.
1. Can they make her pay it back to the estate or withhold that amount from her inheritance to redistribute that portion?
2. Is there any legal reason that this money might come into question or made to be paid back to the estate? i.e.: taxes, financial loss, debt to the decedent, etc...?

Thanks