H1954 That is exactly the attitude you need. Internecine strife between the siblings is nothing to do with you. It is not cruel it is doig your job properly without fear or favour.
In a similar situation to yours, that was our response. DH administered the estate strictly according to the will and with a solicitor doing all the legal work. That one of the beneficiaries felt aggrieved, was nothing to do with us. She got everything left to her in the will and that as far as we were concerned was that.
Parents-in-Law. What do/did you call them?