Hi all, I'm new here...
As for Orthodox rulers, traditionally, they are allowed to enter the altar especialyl during feast days (if they are i ngood standing with the church).
In the Armenian Apostolic Church, there are girls who are called "tubirs" and they are sort of altar girls but they do not say anything in terms of prayers or litanies as far as I know. Once they hit puberty, they stop serving at the altar. I beleive they do things like hold candles, sing in the choir, go in processions- and their clothes are almost identical to the Armenian altar boys'. Also, they wear a veil.
In the Byantine churches, long ago, deaconesses were allowed to receive communion in their hands from the nad of the priest inside the altar but they did not give a blessing. Even a male dezcon does not give a blessing. This si what a priest told me but then again primary historic soruces are few and vague and each local church did things slightly different.