Can a parent sign away your land inheritance to be sold?

My father passed away when I was 9 years old. My mother and him were divorced at the time, and he left no will. At some point my father, and his siblings inherited 160 acres of land each. Therefore since he was deceased my sister and I received it. The land has minerals, and oil on it and we only ever received $60k for it. My mother signed it away to be sold before we were old enough to say so. I am also coming to find out that my mother was bribed with $10k or more to sell the land. She told me if we didn't like her selling it then we would never get anything. She will not provide me with documents of the probate court either. I feel like all of it was extremely shady and we got screwed out of everything. Would there be anyway I could fight this or if it would be worth it since I was not old enough to sign papers?