On the night of Jan. 14, bonfires will light up Morocco as millions of Amazigh people celebrate Yennayer, a time-honored tradition marking both the end of one year and the beginning of a fresh one.

Yennayer is all about family, Tawja, celebrated among brothers, sisters, and grandparents. In Amazigh, Souss dialect, sisters are called Ist ma, which literally translates to «my mother’s ...