The a1c is just an average of your results, if you need to adjust your insulin accordingly, the BG tests are vital, they're the only way you can see patterns with how your body adjusts to food and to insulin. Your diabetic nurse should know that and she definitely shouldn't be telling you they don't matter.
Are you under a hospital clinic or a GP?
I'm under a hospital clinic, I had a few problems some years ago and the consultants at the hospital (as well as my Diabetes Nurse at the hospital) want me to continue seeing them. I am supposed to have appointments every 3-6 months as that is what my consultant wants. (Of course, it doesn't always work out that way, due to cancelled appointments and having to wait at least 6 months usually for the next available appointment). I do know, if I went to my GP's Diabetic Clinic though, that would most likely be a yearly appointment. However, if I had concerns and wanted to be seen sooner, I could arrange that with my GP or DSN.