She wants to assert authority, just let her do whatever she fancies.

My manager is super rude behind me, sending threatening emails to me, but 1-on-1 he’s pretty mild mannered. I just ignore whatever he type that is rude, outright ignoring his emails, but will do his bidding as long as he spoke to me personally.
Cari makan lah. Just to give you an idea how to handle the situation. As long as you’re still needed, they will not burn the bridge, so neither should you. No benefit to being right or to serve your ego.