A 12-year-old patient comes to the clinic. From whom would you accept a valid consent form, EXCEPT:

Valid informed consent for a minor generally must come from a parent or a legal guardian. A grandparent or an adult sibling without documented legal guardianship status does not automatically have legal authority to consent on the minor's behalf, and a 12-year-old cannot give legally binding consent for themselves. The mother (a parent) is the one valid option among these without additional legal documentation.