Every social media site has signalled they're going to ban anything on the right that could possibly be taken as violent or cast doubt on an election. Meanwhile any threats from the left, including organizing riots and threatening the president are tolerated or encouraged.
No reason for her to resign yet. They still need her votes in senate, her judicial committee intel, and they still control the state of California (so they don't need to rush for a dem governor to fill her seat ahead of a party change).
This is more "no reason to resign" than "oh shit I better hang on to my job because Trump is going to declare martial law before the inauguration"