It is note worthy that in a time when women were not highly valued that Catullus supported Sappho's work and in fact mimmicked her style. Were there other women writers one could say he supported?
Well... As far as I know, female writers were a rarity. I know of Sappho as well as you do, and I know of a Latin poetress called Sulpicia, but other than those two, there are not many known female poets from Ancient Rome or Greece. Keep in mind the roles of the genders and the chauvinism that only the lesbian tradition on Lesbos seemed to somewhat conquer.