Is the conure charting dependable?

I recently purchased a cinnamon green cheek and the breeder told me that the DNA testing was not done but since the father is a cinnamon and the mother is a yellow sided that based on the genes the male pes it on to the female offspring and the mom does not so since it is the same color of the dad then it is female... it might not make sense because i don't understand fully when she was explaining this to me. Can anyone please help me understand this better????