I asked my MA supervisor for a reference in early November to apply to an English PhD program at the same institution with her continuing as my supervisor. She agreed. In the subsequent months, we exchange two or three emails just talking about the (re)admissions process and reviewing research proposals. I sent her my final draft of the research proposal in the first week of December and my supervisor said they would look at my research proposal and write my reference over the holiday vacation.
After New Year's Day, 2/4 letters of my letters needed still weren't submitted yet and they were due within a week. I sent my supervisor and the other referee ONE reminder email and they were nearly the exact same in wording. Basically, I wished them a happy new year and politely reminded that the reference letter was due by the end of the week. I said I know they are probably already aware but I just wanted to make sure and act prudently. I also just told her which writing sample I was going to be submitting and left it at that.
My other referee delivered my reference very quickly and wrote back a very nice email wishing me all the best etc. But my supervisor didn't seem pleased. All she said was 'sigh, is the polite version'. I don't know what to make of this response; is it passive aggressive? They did end up submitting the reference the night before it was due, but I am extremely uneasy knowing that I might have done something to piss off my supervisor, who is writing my reference AND serving on the admissions board, AND becoming my supervisor again should I get admitted.
Was I out of line in what I did? Was it possible I could have jumped the gun in sending a reminder a little over three weeks after she said she would get to it over the holiday vacation? But if I was going to send a reminder, I couldn't have waited until after the holiday vacation since the deadline would have already passed. I am not the most socially adept nor am I the best at reading people.