回複：I go back to read my email to boss o, maybe you are

Thanks for explaining to me.

Then, it is up to you to decide (1) to discuss with your boss and the finance vp face to face, in the constructive, supportive manner, to find a solution. MrsD's incapacity is already known to the vp. so be prepared that you may have to spend time, like it or not, not only train her but follow on her for a period of time.

(2) to escalate to the president if you insist this is not your work and refuse to do the extra. I will definitely not recommend it though. Your president would hate you for bringing these petty problems to him.