I added the Churching of the child and the Dismissal from the Diocese of Eastern Pennsylvania below. There are some jurisdictional variances that surprise people when they visit other churches. For example, the placing of the child on the solea after churching is often cause for some befuddlement.
(Stump the Priest) - Question: What is the reason for the difference in practice of churching boys, who are taken behind the altar, and the churching of girls, who are not?Complete post here.
In Baptism, a person is united with Christ and His Church, and becomes a full member of the Church. The Rite of the Churching of an infant who has been baptized is the solemn act of bringing the child into the Church, and offering them to God. Baptisms are now often done inside the Nave of the Church, but historically, baptisms were either done outside (in a flowing river or lake), or in a baptistery that might be separate from the Church altogether, or which is located in the Narthex of the Church. And so, historically, after the Baptism concluded, the newly baptized was brought into the Nave for the first time.
Why is it that boys are brought into the Altar, but girls are only brought in front of the Royal Doors? Both are being offered to God, but their service to the Church in this life will be different. Fr. Victor Potapov says that boys are brought into the Altar, because this is "a sign that he may become a minister of the altar" (On the Significance of the Rite of Churching).
The fact that this has been the universal practice of the Church should be sufficient to convince us that we should accept it, and pass it on without change. However, in our times, when many seek to erase all gender distinctions, many now object to this practice as being "unfair.' And this, of course, also raises the question of having altar girls, as well as the ordination of women.
First off, it should be pointed out that there is not an absolute prohibition against women entering the altar. No one should go into the altar who does not have a blessing to do so. Normally, the altar servers are in fact all male, but in convents, nuns often serve as altar servers, as can been seen in this video which shows Greek nuns censing the Kursk Icon...