Q. 1. All the known angels have male names. I assume that is because they are males. How come we never hear about the female angels in Heaven?
A. 1. It just so happens to be that the known angels have male names. Angels are spirits; spirits are genderless. In order for humans to reproduce in the physical world, God blessed them with a gender. At the resurrection, they will be neither male, nor female.
Jesus said, "For when they (the people) rise from the dead, they neither marry nor are given in marriage, but are like angels in heaven." [Mark 12:25] In other words, there will be no sex in Heaven because the opportunity shall not be there.
In the First Letter to the Corinthians, Saint Paul states: "What I am saying, brothers and sisters, is this: flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. Listen, I will tell you a mystery! We will not all die, but we will all be changed, in a moment, in the twinkling of an eye, at the last trumpet. For the the trumpet will sound, and the dead will be raised imperishable, and we will be changed." [1 Cor. 15:50-52]