sansa the heir to casterly rock?

[Annara Snow]

This time another fragment of the well known, yet so frequently disregarded, SSM. You know which one.

And when Alexander III, King of Scots, rode over a cliff, and Margaret the Maid of Norway died en route back home, and the Scottish lords called on Edward I of England to decide who had the best claim to the throne, something like fourteen or fifteen (I'd need to look up the exact number) "competitors" came forward to present their pedigrees and documents to the court. The decision eventually boiled down to precedence (John Balliol) versus proximity (Bruce) and went to Balliol, but those other thirteen guys all had claims as well. King of Eric of Norway, for instance, based his claim to the throne on his =daughter=, the aforementioned Maid of Norway, who had been the queen however briefly. He seemed to believe that inheritance should run backwards. And hell, if he had been the king of France instead of the king of Norway, maybe it would have.

Yeah, spouses count, and in-laws count, in the game. Sure, under "normal" circumstances, the inheritance goes to the deceased lord's oldest son. Under murky, conflicted circumstances, however, say, should a few blood relatives drop dead, have their right to inherit questioned, have their parentage questioned... well, all kinds of weird shit can go down, and a young, noble, fair Lannister widow pressing her "claim" would be far from the weirdest possible scenario. Saying otherwise simply contradicts what the story tells us, and what the author tells us.

It sure would, if said widow (although I doubt she'll be a widow any time soon or before the end/near the end of the series anyway) were not wanted for regicide and was not completely disinterested in ruling CR or having anything to do with the Lannisters.

[Woman of War]

Any child of Sansa , as long as she is married to Tyrion, would be Tyrion's by law if Tyrion chooses not to declare this child illegitimate or if he dies or disappears before he could possibly do so.

Of course Tyrion would have to have a claim on CR himself. Any king or queen, Jon or Dany e.g., could confirm Tyrion's claim. So Sansa and Tyrion could decide to be together and have a child together, could decide that a child of Sansa by whomever could be Tyrion's by law and his heir - or Sansa's child would inherit as Tyrion's child by law even if Tyrion is dead. Sansa would then be the Lady Dowager of CR.

All depends on who is in power and if these persons are willing to support Tyrion's claim.

There is a lot of foreshadowing that Tyrion might end as father or guardian to a child that is not his, him taking pity in bastards..... So he might decide to bring up an orphaned (bastard) child of dead Sansa as his own, a child that no one else wants.

But that would be independent of CR since I can very well imagine that Tyrion has grown beyond wanting The Rock in the end, that he leaves CR to someone else and prefers to disappear in oblivion and to live a remote life in a small house with a huge library. Obviously Sansa's child would not have a claim either in that case.

Martin has all options here, we will see what might happen.