A Woman Deacons service at the altar
It is true that the assistance of the Bishop at the altar was the duty of the male deacon, rather than that of the woman deacon. It is also true that in the course of the centuries, women deacons may have been progressively more pushed away from the sanctuary, on account of the imagined stigma of menstruation. Yet women deacons were, at least in the beginning, not totally barred from the sanctuary.
Not only was a woman deacon ordained in the sanctuary itself, we know from ancient texts that during the solemn liturgy women deacons, as well as the priests and deacons, surrounded the Bishop during the offering of the Eucharist inside the veil of the sanctuary (see Testament of Our Lord Jesus Christ (late 4th cent. AD), Book 1, § 23.)
From records in the Syrian Church, we know that, with permission of the Bishop, women deacons could fulfil the functions of a male deacon at the altar. With permission of the bishop, the deaconess may pour wine and water into the chalice. (John Telo, Canonical Resolutions, § 38.) Though the rule is from the 9th century, it obviously reflects an earlier tradition.
The we know from similar sources that women deacons were often in charge of maintaining the sanctuary area, as well as the altar cloths.
The deaconess looks after and washes the altar linen. (John Telo, Canonical Resolutions, § 36.)
The deaconess has the authority to sweep the sanctuary and light the sanctuary lamp, and this even when the priest or deacon is not there. (James of Edessa, Canonical Resolutions, § 24; the same rule is also found in the Jacobite Pontifical and in the Nomocanon of Bar-Hebraeus).
The Testament of our Lord Jesus Christ (5th cent. AD) states that widows, among which deaconesses take the pride of place (I, § 40), sit next to the Bishop during the liturgical service (I, § 19). If pregnant women cannot attend the service on a Sunday or feast day, they take them holy communion at home (II, § 20). See James Cooper & Arthur Maclean (ed.), The Testament of our Lord, Edinburgh 1902.
After clearly stating that women deacons have no duties at the altar, and should not touch the altar (notice the fear of pollution through menstruation!!), James of Edessa (end of the 6th cent. AD) records the ancient rule that women deacons may distribute communion to their women companions, if they live in convents: If a deaconess lives in a in a community of nuns, and there is no priest or deacon, she may take the holy sacrament from the tabernacle and distribute this to the women who are her companions, or to children who happen to be there. (James of Edessa, Canonical Resolutions, § 24). The same tradition was still known in the Middle Ages, when abbesses had taken over some of the privileges of deaconesses. They distributed communion and read out the Gospel in their own chapels; see Huguccio (Summa, 1188 AD).