The Mishnah (Berachot 20b) states that women are obligated in the Mitzvah of prayer. The Gemara explains that although there seems to be sufficient reason to exempt women from prayer as it is a positive, time-bound Mitzvah, nevertheless, since prayer entails requesting Hashem’s Heavenly mercy, which women also require, women are likewise obligated to pray and this is not, in fact, considered a positive, time-bound Mitzvah. “Prayer” in this context refers to the Amida prayer.
The Poskim disagree regarding the explanation of the above Gemara. Some say that women are just as obligated in the Mitzvah of prayer as men and at the very least, they must pray Shacharit and Mincha every day. Others say, however, that women are only obligated to pray once a day, as this constitutes the primary Mitzvah of prayer. It was our Sages who enacted that we pray three times a day and women were not included in this enactment.
Halachically speaking, according to the opinion of Maran Ha’Shulchan Aruch and the custom of Sephardic and Middle Eastern Jews, women are only obligated to pray once a day, either Shacharit, Mincha, or Arvit. This is a woman’s holy obligation and one should not try to shirk it, G-d-forbid. According to the Ashkenazi custom, however, some say that women are obligated to pray Shacharit and Mincha every day. There is room not to obligated even Ashkenazi women in the Arvit prayer since Arvit was accepted as an obligatory prayer only by men and not by women.
Maran Rabbeinu Ovadia Yosef zt”l would advise that women should establish one set prayer per day, either Shacharit, Mincha, or Arvit, so that they can recite that prayer on a consistent basis and not miss praying for an entire day. It is especially worthy that a woman recite the Shacharit prayer and before doing so recite the “Birkot Ha’Shachar” (the morning blessings which women are obligated to recite every day, besides for the “She’lo Asani Isha” which women substitute with the “She’asni Kirtzono” blessing albeit without reciting Hashem’s name), followed by “Birkot Ha’Torah” (the daily blessings of the Torah), and then preferably followed by the verses “Shema Yisrael” and “Baruch Shem Kevod Malchuto Le’Olam Va’ed.” Whenever possible, a woman should all three chapters of Keri’at Shema and then begin the Amida prayer.
If a woman can, she may pray all three daily prayers. Even according to the Sephardic custom that women do not recite blessings upon Mitzvot they are not obligated to fulfill, this does not apply to the Mitzvah of praying and a woman may recite all of the blessings included in the Amida prayer even three times a day, as many righteous women do.
Mrs. Simcha Tzadka, of blessed memory, a truly righteous and upstanding woman who was the mother of Hagaon Harav Yehuda Tzadka zt”l, legendary Rosh Yeshiva of Porat Yosef, was well-versed in laws and their sources and would arrive at the synagogue every morning and begin praying with the first Minyan for Shacharit and would conclude her prayers along with those praying in the second Minyan. She would likewise pray all three daily prayers with a Minyan in the synagogue. There are many other righteous women who acted in this manner, especially when they were older and were no longer as busy with child-rearing as they were in their youth. They therefore utilized their spare time to immerse themselves in prayer with intense dedication and they would pray at length for their children and grandchildren. Nevertheless, women who are busy raising a family may not leave their children pursuing lengthy prayers, Tehillim reading, and participating in Torah classes all day long as everything has a time and place.