There is a machlokes haposkim how one should celebrate Bat Mitzvahs. Swiping from Harav Daniel Neustadt:
Rav Walkin (Zekan aharon 1:6)holds bas mitzvahs are a goyishe custom and should be avoided.Rav Moshe feinstein ( OC 1:104) holds it’s like any other birthday party and is not a seudas mitzvah. The Sridei Eish 3:93 and Rav Avadia yosef (Yabia Omer 2:29) hold it is a seudas mitzvah. However, both The Igros Moshe and the Sridei Eish holds it shouldn’t be celebrated in a shul.
Rav Moshe ZT”l clarifies in OC 2:97 why a girl’s bas mitzvah is treated differently from a bar mitzvah. The boy undergoes a change in his public mitvzah obervance (Tefillin, minyan, etc) and this warrants a public celebration. The girl’s change is in private observance, and this does not warrant a party. I would like to look up these Igros Moshes inside, since the Zohar which is the source for bar mitzvah celebrations would lechora apply to both.