1) How much is involved here?
2) How much cash assets?
3) How much are the debts of the two siblings?
4) Has this will been submitted to the probate court?
5) Are the assets in the estate all cash?
6) Is there any dispute over the amount of the loans? Is anything in writing?
Divide the cash assets into three equal shares. Then subtract the debt from each sibling. Then divide the remaining balance (the combined debt) into three shares and add that to each siblings share.
So if the estate had a value of $12,000. Divide that into three parts ($4,000). One sibling owes zero, one sibling owes $500 and the other owes $2,000. You would then have sibling "A" with $4,000, sibling "B" with $3,500 and sibling "C" with $2,000. That would be $9,500 total. The remaining $2,500 would be split three ways. Sibling "A" would end up with $4,833.33, sibling "B" would have $4,333.33 and sibling "C" would have $2833.33.