Despite what I wrote two hours ago, I was just notified by my Brother Dov that he discussed the issue with Rav Asher Weiss Shlita last night at his Thursday night Shiur in Har Nof Jerusalem. Rav Asher holds that as long as there is continuity, the girl can continue counting with a berakha after her bat Mitsva.
Yiyasher Kochacha and Shabbat Shalom
Aryeh