So, right now in my department, we have 3 people, including me. I've been with this organization for only 4 months. Anyway, our boss is very high in our organization and doesn't manage us. He lets my senior coworker with 30+ years of experience to run the department. This senior coworker has been at this organization for 2 years. I only have one year of experience before joining at this organization. Anyway, we recently hired the 3rd coworker. Before I started, 3 people left within 3 months due to my senior coworker. Because she runs the department, she treats anyone who knows less than her like shit. She micromanages and assigns multiple tasks and expects the tasks to be done immediately. Honestly, my first two months with her were miserable, especially since I had to share a room with her. Then, we hired a 3rd coworker and the new one took my desk so she now shares room with my senior coworker. I have my own cubicle outside of the now room. The 3rd coworker has one year of experience like me, but she knows way less. She is very nice to me. She takes forever to do one thing. Within 8 hours, she would only get two tasks done. She takes one hour to do something I can for 15 minutes. Anyways, the senior coworker has been treating me so well now because she needs allies to get rid of the new coworker. Tbh, they both deserve each other because the senior coworker treats people like shit. For example, she would assign me something at 1:50pm when I have a meeting at 2pm then she expects me to finish the assignment at 3:10 when I literally just come back. Anyway, I'm just here laughing because my senior coworker deserves a slow person like my 3rd coworker.
I do not want to lose my 3rd coworker because I need allies. I told her that our role has more tasks to do, but she didn't understand and probably thought I was acting like her boss. So, as a result, I backed off.
How do I tell her? Should I just stay quiet?