Bar/bas mitzva Celebration

Igros Moshe (OC I #104) Question Can you celebrate a bas mitzva in the same way as a bar mitzva? Answer  Under no circumstance should a bas mitzva be celebrated n the synagogue even at night! That is because the celebration of a bas mitzva is not considered a mitzva.  It is especially problematic since the idea for this celebration is from the Reform and Conservatives. While if the father wants to make a celebration in his home it is appropriate but just understand this is not considered a mitzva at all but is no more than a birthday party. In fact if I had the power I would eliminate in America the celebration of a bar mitzva. Since as is well known this doesn’t bring anyone closer to Torah and mitzvos including the bar mitzva boy himself. In fact the opposite is true that many times it causes profaning Shabbos and other sins.  However since the bar mitzva celebration has become the standard practice and in addition it is associated with mitzva it is difficult to stop it. Nevertheless with regard to the bas mitzva celebration it has no associated mitzva at all. So it is best to refrain from even celebrating it in the house even though it is not prohibited. Surely it is prohibited to be done in the synagogue even at night when people are not praying. 

Igros Moshe (O.C. II #097): Question You asked why there is no meal for a bas Mitzvah who is 12 years old like is made for a bar mitzvah since she is now obligated to keep mitzvos? Answer Let me add and reinforce the question. Even though the girl does not give a speech and even if she did it means nothing since she is exempt from Torah Study nevertheless on the day of a bar mitzva the meal is a meal of mitzva even if the boy does not give a speech so it should also should be considered a meal of mitzvah on the day of Bas Mitzva? A possible answer is that it is not obvious with a girl that her status has changed and she is no longer a child.  With a boy he is now counted as part of a minyan and is counted as part of three that require Zimun. In general If it not obvious that a change has taken place we don’t make a festive occasion or meal. Since the boy can now also say Berachos and prayers as well as the Hagada for others it is obvious his status has changed and that justifies making a festive meal. In contrast with a girl it is not obvious that her status has changed and thus we don’t make a festive meal.

Igros Moshe (OC IV #36) Question What is the significance of the celebration of a bas mitzvah Answer The meal for a bas mitzva is not a seudas mitzva (meal of mitzva) but is merely a birthday celebration and therefore it should not be done in the synagogue. However to make a kiddush in shul is the common practice in America as is the practice for all joyous occasions. It is also appropriate to say things in honor of the Simcha. However the speeches should not be made from the bimah in the shul but at the table where the kiddush is served. If it was already decided otherwise to make a more elaborate celebration and changing it to a simple kiddush is regarded as insulting and will cause disputes, then the original plans should be followed. But in the future make only a simple kiddush that would be made for other simchas. There should be no celebration which causes degradation and profaning Shabbos and other problems even for a bar mitzva even if the intent is to bring people closer to Torah and mitzvos. Even if this might be true for a particular girl, but for  most girls it is best to avoid this new innovation of an elaborate bas mitzva but as I mentioned disputes need to be avoided