I am aware of potential sibling trouble which is why I am avoiding complications. Two girls close in age they are good friends.
I don't and won't own any property which helps. If I have anything left they get half each. Simple although the Boat situation could be tricky I suppose.
Luckily my sisters and I never get any conflicts around money because we know, from mother's side of the family, that it is not worth losing family relationships over money. Blood is thicker than water.
Interesting to observe the different ways people handle having a lot of money. Some are very defensive and end up loaded while others just throw caution to the wind and end up with not much but they probably had more fun on the journey and did not spend their time screwing over other people.