The first child of the union between Amram and Jochebed, his wife, who was one hundred and twenty-six years old at the time of her marriage, was a girl, and the mother called her Miriam, "Bitterness," for it was at the time of her birth that the Egyptians began to envenom the life of the Hebrews. The second child was a boy, called Aaron, which means, "Woe unto this pregnancy!" because Pharaoh's instructions to the midwives, to kill the male children of the Hebrews, was proclaimed during the months before Aaron's birth.
Miriam's Name Means Bitterness for the Suffering of Her People
Legends of the Jews 4:41