Hi
You have been working hard and I am impressed by what you have found out. It does help clarify things. The birth date of 1862 for Agnes GENTLES PATRICK SCOTT is later than the one I had previously found and fits better with the marriage date of the parents. I have no record of her death but she does not feature in any census data I have seen.
I have re-checked the executor accounts for Robert PATRICK and there looks to have been three legatees - Agnes GENTLES SCOTT, Alexander STEVENSON SCOTT and Robert PATRICK McMULLEN. Agnes was the principle legatee and my records show that she was receiving £12/month from the estate in 1912. Alexander got a watch and chain which would have been no use to him because he died the year before! Robert received £100.
Many thanks for getting things this far. I still have a few credits on SP, so I will dive in again and see how fare I can get base don what you have found out.