Is it possible for your hair to stop growing at a certain length?

My hair stopped growing in the middle of my back. It's never grown to my ass. Yes I said ASS. Deal with it! Anyways I have a friend that's jealous of women with long hair, espcially the black ladies since she is black herself. She complains that her hair NEVER grows past her shoulders. It always stops by her neck. She said her hair broke off a lot in the past but it's all even. It's still won't grow and she said it's been the same length for two years. She said some women I her family (moms) said have LONG natural hair and even her mom did so why hasn't she? Also she said she stopped putting perms in her hair and her hair is STILL the same length. She is so mad that she is giving up trying to grow long hair. She is very fustrated. She said she keeps her hair moist.