If a lord already has a bastard, then marries a lawful wife, she is not his "stepmother" and has no obligations to him (Catelyn was never considered Jon Snow's "stepmother", nor did even Jon expect her to treat him as such).

Thus Walda was not Ramsay's stepmother in Season 4.

However, on being legitimized, Ramsay became Roose's lawful son, and thus from the end of Season 4 onwards, Walda is Ramsay's stepmother.--The Dragon Demands (talk) 18:47, December 24, 2017 (UTC)