I want to apply to epidemiology programs this cycle (I am down to the wire here, I know), and one of the key professors I have in mind for a recommendation letter was my Epidemiology professor whose class I got an A in and was selected as a Teaching Assistant for the following semester.
The problem is, when I was taking her class, someone had raised their hand to ask if she writes recommendation letters for students if they're taking gap time before applying (or something along those lines), and she had replied saying that if we'd like her to write a recommendation for us in that situation, we should contact her once a year until that time.
Now...I didn't do that - looking back at my emails, I had contacted her a year after I TA'd for her to ask if she'd be a job reference in fall of 2017, which she had happily agreed to do. Then I didn't have any correspondence in 2018, and the next time I reached out was April 2019 to ask if she'd be a job reference and if she'd be a recommendation writer if I applied that fall, which I didn't end up doing - she didn't reply back.
So anyways it's been basically 3 years since a successful interaction with her, and I'm wondering how people would recommend reaching out to her now and what would be a good way to phrase my ask.