The following prayer is from the Talmud, and the beautiful text is as meaningful today as it was over 2000 years ago when it was first written and is appropriate to be quoted at a Bat Mitzvah ceremony.
Talmud Berachot 17a – Lawrence Kushner, Translator
May you live to see your world fulfilled,
May your destiny be for worlds still to come,
And may you trust in generations past and yet
to be.
May your heart be filled with intuition
and your words be filled with insight.
May songs of praise ever be upon your tongue
and your vision be on a straight path before you.
May your eyes shine with the light of holy words
and your face reflect the brightness of the heavens.
May your lips speak wisdom
and your fulfillment be in righteousness
even as you ever yearn to hear the words
of the Holy Ancient One of Old.
Bat Mitzvah Prayer, image from pearleditions.com