If she had several daughters? Why, that’s easy: Prima, Secunda, Tertia… et cetera. No need to give them ‘real’ names. Numbers worked just as well.
And you are absolutely right. I get so enamoured with the misogynistic culture of the Romans (to the point of not differentiating women except for their relations to men), that I conflate it with other androcentric practices in my mind.
Yeah, I was guessing something like “Juliae!”
On HBO’s Rome Lucius Vorenus had two daughters, naturally both named Vorena. He simply called his older daughter, Vorena the Elder, “Eldest”.