How to remove someone from my Instagram

Sorry I know this may be the wrong forum but I couldn't see one that fitted my dilemma.
I have an Instagram page which is open but anonymous as I talk about finances and mental health. I, stupidly, told my work colleague/kind of friend about it and she added me. Her posts are slightly annoying at the best of times, she over shares things and are a bit attention seeking. Anyway we had a slight falling out and she posts a story on her Instagram that was blatantly aimed at me, although didn't specifically say that it was but now I don't trust her with the content of my page. Problem is we work practically opposite each other and have breakfast/lunch together every day and I don't want to make things awkward. How can I delete her or stop her seeing my content without making the situation awkward?