Am I wrong for protecting my mom?

Let me add some details and plus I need to vent me and my mother moved from my hometown Las Vegas to help out a family member who have a heart condition.. this family member is a froster parent it’s not easy taking care of children but she doesn’t want the children who are respectful and kind but she wants the ones who are indeed mentally ill with trauma and want to be passive aggressive.. this one child my family member is keeping is passive aggressive to the point she will call the cops so she puts this child on my mom and or me when she not feeling good.. my mom got mad at me for standing up and being protective over her when this child had put hands on me before and he would try to get passive aggressive with my mom.. my mom was shaking from the incident even tho she tries to hide it but am I wrong for trying to protect my mother

Am I wrong for protecting my mom?
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