Miriam was born on May 24, 1927 in Kalisch, Poland, daughter of Moshe David and Bilhah. She made aliyah with her family at age six. She spent most of her time in Ir Ganim, today part of Kiryat Ata.
Her father, Moshe David Onikovksy, served in the British Army during World War II, helping the Allied cause. This inspired his daughter with her love for the homeland and the legacy of Israel.
In 1944, Miriam joined Lehi. She put up posters in and around Haifa, and among her activities was surveillance in preparation for the attack on the Haifa Railway Workshops.
In May 1948, she joined the IDF, becoming the first woman to achieve the rank of first sergeant, as quartermaster of the armored company of Battalion 82. She served with the company throughout the War of Independence.
After the war, she married Siman-Tov “Menahem” Niago, another Lehi member. They had two daughters, Athaliah and Orli, and three grandchildren.
In 1964, they moved to Safed, where Miriam opened an art gallery.
Miriam passed away, after a severe illness, on September 1,1993.