We have explained the primary laws of Zimun that if three men eat a bread meal together, they must perform a Zimun before reciting Birkat Hamazon. This is done by the leader proclaiming, “Nevarech She’Achalnu Mishelo” and the others replying, “Baruch She’Achalnu Mishelo Uvtuvo Chayinu.”
We have been asked by many: Do three women who have eaten a bread meal together perform a Zimun as do three men?
The Baraita in Masechet Berachot (45b) states: “Women perform a Zimun for themselves.” We see that if three women eat together, they do indeed perform a Zimun before beginning Birkat Hamazon the same way men would.
The Rishonim nevertheless disagree about the meaning of this Baraita: Does it mean that three women who ate together must perform a Zimun or does it mean that they are permitted to do so if they wish to?
Halachically speaking, women are not obligated to make a Zimun when eating together and it is merely optional. Maran Ha’Shulchan Aruch rules likewise (in Chapter 199). Nevertheless, several Acharonim, including Hagaon Rabbeinu Yosef Haim of Baghdad and others write that although the custom in most places is that women do not perform a Zimun when eating together, it is nevertheless preferable that if three women have eaten together that they perform the Mitzvah of Zimun, for it is indeed invaluable. This is especially true since according to some Rishonim, their Zimun is mandatory and not optional. Thus, in order to fulfill all opinions, it is proper for women to perform a Zimun after eating together.
Nevertheless, when men and women are eating together and three men who have eaten are present, there is certainly no need for the men and women to split up and each recite their own Zimun, for the women fulfill their obligation with the Zimun performed by the men.
If ten women or more have eaten together, the is a disagreement among the Rishonim if they add Hashem’s name to the Zimun by reciting “Nevarech Elokeinu She’Achalnu Mishelo” as would be the case regarding ten men or if they should merely recite a Zimun without mentioning Hashem’s name, meaning that there is no distinction whether there are three or ten women present. Halachically speaking, women should not recite Hashem’s name in a Zimun they are performing for themselves, for some are of the opinion that in order to recite Hashem’s name in a Zimun, there must be a quorum of ten adult men just as is the case regarding praying with a Minyan. Thus, women should not recite Hashem’s name in their Zimun.
Summary: Three women who have eaten together do indeed recite a Zimun before Birkat Hamazon as men do. Nevertheless, this is not mandatory, but the Poskim write that it is especially recommendable to do so. Women should always perform the Zimun by saying “Baruch She’Achalnu Mishelo” and they should not mention Hashem’s name in their Zimun, even if ten or more women are present.