Say for instance your mom's name is Teresa, you are Teresa's daughter and Teresa's daughter is you. Say you also have a daughter, only you can be your daughter's mother.. right? Therefore Teresa is your daughters grandmother and you are Teresa's DAUGHTER.
Lets review: Q. If Teresa's "DAUGHTER"(you) is "My" daughter's mother who am I to Teresa?A. You are Teresa's DAUGHTER.
Teresa is your mother. and you are your daughters mother