I have to say that a spouse without a bloodline claim on their own right inheriting seems really jarring to me. It is fantasy so I guess things could in theory work that way, but it is quite ahistorical and would seriously alter how royal marriages are arranged in the first place.
Edit: And yes, I know this happened in GoT and it bugged me a lot.
I understand it odd in history, but what reason would they have to dispose a queen who co ruled with her husband for years in favor of a child? Not "that's how it was in history" but my players will want a reason for it to make sense in the game world (were again we don't do sexism so no 'cause she was the queen')I remember this being important to some of the plot points in Dimension 20's A Crown of Candy, and I found it odd as well. It's probably intuitive to a lot of people since it's how modern property inheritance generally works, but it's an odd fit for a pseudo-medieval setting where creating shared political interests (primarily through shared descendants) is the main point of the marriage. It also creates very obvious assassination incentives if the spouses don't actually like each other or if there are non-shared children in the picture.
In modern day when my grandfather died everything went to my grandmother, when she passed it was passed to there children and grand children.