Child protective services help?

I graduated from high school last year and was very well liked( popular,captain of the sports teams, prom king, etc.) I had a rough childhood, but my mother(single mother of 5) was there working and going to school both full time to help better our lives. My little sister is now a freshmen at the same high school. She is getting picked on, pushed around, beat up, etc. She does not share the same last name which is why I think they don't put our connection together, but what had happened was she became very depressed. My mother tried to seek a counselor to help but the school ignored her. She repeatedly called the principal and asked for something to be done. They didn't. My sister tried cutting herself once and she told a who friend told a counselor. Now there is a huge ordeal and CPS is trying to call my mother up on neglect and abuse, both of which she has done nothing close to doing. She is a nurse and can lose her job and her future simply by being ociated with an abuse case. I am now of age so the people at CPS refuse to talk to me in regards of the situation. How is that fair? Simply because I'm a legal adult means I have no recollection of my childhood under my mother? How is that even considered a logical reasoning? I know my mother has not abused us and she never would. Is there anyway I can legally get involved? This is both unjust and unfair. Serious answers only please. This is in upstate NY if that means anything. Thank you for taking the time to read.