Did you realise in advance how your mother will be as a mother-in-law?

You have seen your mother everyday while growing up. For reasons, it's often seen that women turn toxic towards their DIL and SIL and try to play politics, assert dominance and manipulate the mind of their own child against their spouse.
Do you think it is possible to judge how your mother will be as a MIL after you get married? Can a woman who is literally so good transform into something else? Or is it that "bad" MILs possess that nature innately?