If the Muslims have a problem with that then this school is probably not for them.
That said, if the women's auxiliary has a 90% male membership, it's not the women's auxiliary anymore and those responsible for membership ought to have realized this very early in the peace.
With regard to the school, local Catholics have either moved out of the area and abandoned it to the Muslims and/or simply abandoned the faith and ceased sending their children to the Catholic school.
Either way, this is what happens when a Catholic population which dwindles in either fervor and/or numbers is replaced by another religious group which takes itself seriously. If those responsible for admissions to this school had been serious about safeguarding the school's Catholic identity, they would never have allowed this situation to develop.
This is a microcosm of what's happening all over Europe. Muslims moving in by the millions and having as many babies as possible. Local population dwindling.