(1) And the LORD spoke unto Moses and Aaron in the land of Egypt, saying: (2) ’This month shall be unto you the beginning of months; it shall be the first month of the year to you.
Talmud Yerushalmi Ta'anit 1:6
Women who refrain from work on Rosh Chodesh [= the first day of a lunar month] are following an established custom.
וא"ר אחא בר חנינא א"ר אסי א"ר יוחנן כל המברך על החדש בזמנו כאילו מקבל פני שכינה כתיב הכא (שמות יב, ב) החדש הזה וכתיב התם (שמות טו, ב) זה אלי ואנוהו
R. Aha b. Hanina also said in the name of R. Assi in R. Johanan's name: Whoever pronounces the blessing over the new moon in its due time welcomes, as it were, the presence of the Shechinah: for one passage states, "This month;" while elsewhere it is said, "This is my God, and I will glorify Him."
Pirkei d' R. Eliezer, 45
When the Jews asked Aaron to make them a golden calf, Aaron said to them, "Remove the rings that are in the ears of your wives (Sh'mot 32:2)." The women, however, did not agree to give their jewelry to their husbands. Rather, they said to them: "Should we make a calf which is an abomination and has no power to save us? We will not listen to you!" Hashem rewarded them in this world that they keep Rosh Chodesh more than the men do. He also rewarded them in the world to come that they will be renewed like the Roshei Chodoshim, as the verse says: "Your youth shall be renewed to be [as light] as an eagle (Tehillim 103:5)."
Kiddush Levana (Sanctification of the Moon) Blessing
Blessed are you, God, ruler of the universe,whose word created the heavens and whose breath created the heavenly hosts, who gave them ordinances that they not change their orbits. Joyful and happy are they to do the will of their creator, a worker of truth whose work is truth! To the moon God said; renew yourself, crown of glory for those borne in the womb, for they like you, are destined to renew themselves,and to give glory to their creator for the sake of God's holy honored sovereignty (malkhut/Shekhinah). Blessed are you, God, renewer of months.
A woman’s body is characterized by "cycles of change” as women go from one stage of life to another: puberty, menstruation, pregnancy, birthing, breast-feeding, and menopause. “Likewise,” she writes, “each month the moon waxes and wanes with a comforting predictability” (33). She further writes: “All throughout the generations women have experienced the same cycles of life. Like the familiar moon, the body gently speaks to us. The moon’s cycles are reflected in our counting and deposited in our bodies. One can look at the moon to observe its phases, and likewise, a woman can observe her internal body changes."