Here is Canon 19 from the First Ecumenical Council (Nicea, 325):
CANON XIX.
CONCERNING the Paulianists who have flown for refuge to the Catholic Church, it has been decreed that they must by all means be rebaptized; and if any of them who in past time have been numbered among their clergy should be found blameless and without reproach, let them be rebaptized and ordained by the Bishop of the Catholic Church; but if the examination should discover them to be unfit, they ought to be deposed. Likewise in the case of their deaconesses, and generally in the case of those who have been enrolled among their clergy, let the same form be observed. And we mean by deaconesses such as have assumed the habit, but who, since they have no imposition of hands, are to be numbered only among the laity.
Notice that deaconesses had "no imposition of hands" and were "to be numbered only among the laity."
So much for the idea that deaconess is just the female flip side of the office of Deacon.
I recall reading somewhere that deaconesses assisted with the baptism of women and with charitable service to widows and orphans.
They were not actually ordained and did not serve at the altar.
