There is some controversy among the Halachic authorities concerning the permissibility or advisability of Bat Misva parties celebrating a girl’s twelfth birthday, the point at which she becomes obligated in Misvot.
Let us first briefly examine the parallel custom of holding a festive celebration when a young man reaches the age of thirteen and assumes the responsibilities of Misva obligation. The Maharshal (Rabbi Shlomo Luria, 1510-1573) suggested that the source of this time-honored practice is a comment by the great sage Rabbi Yosef, cited by the Talmud in Masechet Kiddushin. Rabbi Yosef was blind, and though one opinion among the Sages held that the blind are exempt from Misva obligation, he nevertheless fulfilled all the Misvot. Initially, Rabbi Yosef had hoped that Halacha would follow the view exempting the blind from Misva obligation, so that he would receive extra reward for performing the Misvot despite his condition. However, he then learned the principle that performing the Misvot that one is obligated to perform is greater than performing Misvot from which one is exempt. At that point, he remarked that to the contrary, if he would be told that Halacha follows the view obligating the blind in Misva performance, he would host a festive party, celebrating his obligation in Misva observance.
This demonstrates that one should hold a celebration upon discovering that he is obligated to observe Misvot. Certainly, then, one should celebrate on the occasion of a Bar Misva, when a young man actually becomes obligated in Misva observance.
At first glance, this rationale should apply equally to young men and young women. When a young woman reaches the age of twelve, she becomes obligated in Misvot, an occasion which, as we have seen, warrants conducting a festive celebration.
Nevertheless, Rabbi Moshe Feinstein (Russia-New York, 1895-1986), in several instances in his Iggerot Moshe, opposed the practice of Bat Misva celebrations, and drew a distinction between the occasion of a boy reaching the age of thirteen and a girl reaching the age of twelve. When a boy reaches the age of Bar Misva, this occasion is publicly evident. For example, he wears Tefillin in the synagogue and can be counted toward a Minyan. People around him can immediately recognize that he has become obligated in Misvot. The same cannot be said about girls; when a girl reaches the age of Torah obligation, there is no outward, discernible sign of her new status. As such, Rabbi Feinstein claims, a celebration is warranted when a boy reaches the age of thirteen, but not when a girl reaches the age of twelve.
Likewise, a number of other Halachic authorities opposed Bat Misva celebrations because of the likelihood of breaches in proper standards of Seniut (modesty) at these events. The girl might address a mixed audience, and her friends may sing and dance in the presence of men, thus transforming what is intended as the celebration of a Misva into a situation of misconduct.
However, several other authorities, including Hacham Ovadia Hadaya (1890-1969), in his work Yaskil Abdi, as well as Hacham Ovadia Yosef, permit Bat Misva celebrations, assuming, of course, that they strictly comply with proper standards of Seni’ut. Hacham Ovadia Yosef noted that nowadays, as opposed to earlier generations, both boys and girls receive a formal Torah education in religious schools, a development that has resulted in an equality of sorts with regard to children’s religious training. As such, girls will naturally and justifiably feel slighted if celebrations were held when boys reach the age of Misva obligation, but not when a girl reaches this milestone. This may also result in a Hillul Hashem (disgracing of Torah). Therefore, assuming the celebration is a low-key, tasteful affair, conducted in strict compliance with the laws of Seni’ut and in the presence of respected Rabbis, such celebrations are entirely permissible and in fact appropriate.
Furthermore, the Ben Ish Hai (Rabbi Yosef Haim of Baghdad, 1833-1909) writes that it is proper for a girl to receive a new dress on the occasion of her twelfth birthday, and to recite the Beracha of "Sheheheyanu" when wearing the dress for the first time on her birthday.
In conclusion, we must emphasize the importance of modesty and avoiding outlandish extravagance in hosting these kinds of affairs. We have already seen, unfortunately, how even Bar Misva celebrations have become overly elaborate and wasteful. It would be truly a shame if this regrettable trend would extend to Bat Misva celebrations, as well.
Summary: It is appropriate to host a modest, tasteful Bat Misva celebration when a girl reaches her twelfth birthday, assuming that it is conducted in accordance with proper standards of Seniu’t (modesty) and in the presence of respected Rabbis.
