From a 16 year old’s standpoint:
Women were not allowed to serve in the Old Form, so why would that have changed when the current Ordinary Form was created? If the Old Form community wants to stay as it was before, then let them. I prefer the Ordinary Form, I have no problem with them saying they want it as it was.
That said: To the arguments that Boy are doing this as training for the priesthood, I must disagree. I altar serve, and love doing it, and indeed am discerning a call to the priesthood. However, I am far from the normal 16 year old in terms of faith.
Most guys altar serve for 2 reasons.
- There parents make them because they need boys
- There are girls
Altar serving is important. It gives an average kid the ability to help closely celebrate the Mass. It causes religious interest. I’ve heard Mass attendance is the lowest it has ever been. At a point like this, should we really be restricting who and who can’t serve? I know people will say that “It is a tradition”, and you are right, as I stated above. Then again, the Apostles did not have music, wear vestments, or speak in Latin. Should we go that far back to maintain an authentic Catholic view? Yes, I am exagerating, but to prove a point.
Secondly, people saying that kids are showing up for the TLM. I have been to 4 TLM masses recently, just to see what they are like. I have seen very few kids. Very few. Those there appear to me (I am also a kid) that they are not interested. Rather, they are there because their parents brought them along.
Instead of restricting girl altar servers, in a form of the Mass that is not well attended, why not focus on issues that are truly hurting the Church.

Because lets be honest. What harm is girls helping on the altar. They are 12-16. Not feminists bent on the destruction of the Church.
Pax vobiscum