Miriam wasn't attending the Synagogue which was ADDED after the fall at Mount Sinai.
Don't forget that God slapped Miriam with a dose of leprosy when she claimed that she was a PROPHET and therefore speaking for God. We don't hear much about her. In fact, Miriam would have been considered a "princess" and therefore automatically a Prophetess of Hathor as the female part of Apis the golden calf at Mount Sinai.
Ex 15:20 And Miriam the prophetess, the sister of Aaron, took a timbrel in her hand;
and all the women WENT OUT after her with timbrels and with dances.
Thus saith the Law:
Here is what Miriam really did:
Yaca (h3318) yaw-tsaw'; a prim. root; to go (causat. bring) out, in a great variety of applications, lit. and fig... break out, ..be condemned, departure), draw forth, escape, exact, fail, fall (out), fetch forth (out), get away.. lead out, pluck out, proceed, pull out,
And Cain went out from the presence of the Lord, and dwelt in the land of Nod, on the east of Eden.Ge.4:16