I am applying for Masters programs and I am trying to get my letters of recommendation squared away. One of the professors I asked has failed to respond to my emails. I sent her an initial email a month ago, and a follow-up email at the beginning of this week. This professor seems like my best option for a recommender, so I'm very reluctant to try to find someone else.
I truly cannot think of a reason why my advisor/professor would decline to write me a letter, but I wish she would at least answer yes or no. Should I continue to contact her? Should I try calling during her office hours? See if I can set up a Zoom appointment with her? Or, should I find someone else, even if this would just be someone I took a single class with?