A manager being hostile and sabotaging crew members

There is a female manager at my location that likes too spread rumors about other crew members two other managers she also bullies me on the overnight shift and the other employees on the overnights have noticed it and she also has lied about her birth year on her application so that she could be a manager before she turned 18 she just turned 18 last month and she’s been a manager for at least six seven months now from what I’ve been told as she is the one going around telling people that she lied about her age to do so and telling us not to say anything The bullying and the yelling and screaming at people and rolling her eyes and rolling her head while talking to people is very disrespectful. The manager who I am talking about her name is Gabriella.