We have a lot of documents from early church fathers, who were as far as I'm aware always male, but is there any accounts of females acting in a leadership or authority role similar to that of the early church fathers in the same period, between 100 and 350 AD?
The role of deaconess was provided in the early Church. There is a discussion of this in the answer to:
The Apostolic Constitutions declare:
Ordain also a deaconess who is faithful and holy, for the ministrations towards women. For sometimes he cannot send a deacon, who is a man, to the women, on account of unbelievers. Thou shalt therefore send a woman, a deaconess, on account of the imaginations of the bad. For we stand in need of a woman, a deaconess, for many necessities; and first in the baptism of women, the deacon shall anoint only their forehead with the holy oil, and after him the deaconess shall anoint them.
But this was not a leadership role, as you suggest. From Apostolic times, women were specifically excluded from assuming any sort of leadership role in the Church. This is obvious from Paul's admonition that women should not even speak in the Church (1 Corinthians 14:34). The only possible exception might be the role of abbess, which developed in the 3rd century as monasticism took hold in Egypt and elsewhere. Even here, though, a women's monastery (or "convent") required the occasional service of a (male) priest to administer the sacraments.