You can describe your family as matriarchal if it is full of strong women, headed by your feisty grandmother. A group or society is matriarchal when it is run by women.
Anthropologists use the adjective matriarchal to talk about societies that are headed by females. The word comes from the Greek matēr, "mother," and archein, "to rule." The term matriarchal arose as a balance to the traditional patriarchal, male-ruled, concept of society, although feminists and anthropologists often use it to describe societies in which women have equal rights, as well as families or tribes headed by mothers or grandmothers.