Decision Authority

Our nanny has been with us for 7 years. I work from home, and the doors to my office have large windows - you can look into my office and see my computer screens. A couple of times each week, probably more days than not, our nanny will knock on the door to give me an update or ask me a question. She seems to think that as long as I'm not in a meeting, it's an appropriate time for her to knock and speak with me. Frustratingly, it's typically when I'm not in meetings that I need the most concentration for my work. Commonly my children also follow her into the office and then ask questions themselves.

The questions are along the lines of 'child X wanted this lunch instead of that lunch, is that okay?' Or 'we were going to go to the park but it's raining so is it okay if we stay home?'

Am I off base for feeling like our nanny, especially after this many years with us, should be confident enough in herself to make these decisions? To me, these decisions are part of the job description of being a nanny.

To be clear, this also occurred when she was new with us and has occurred consistently over the time, but I find my frustration continuing to grow. 95% of the time my answer is "yes that seems reasonable". I don't feel like I am micromanaging her or the kids.