As someone who has been a professional musician, music teacher, worship leader, music director, and musician in church for 36 years since I got saved, I think this is not really about music.
This girl (woman) must love music to come to choir practices and sing in the choir. If it is a biblically based church (I assume it is!) then the music must be glorifying God, and maybe incorporate some Scripture in the music, or maybe doctrine if some older hymns are sung. (Maybe not?)
So this young person is hearing, and probably memorizing words of truth about God, Jesus and following him. Even if she is not following him! So if this young woman was kicked out of the choir, would she ever come back to church again? Would she ever hear the words of life contained in these songs? Or would her world become the world of only darkness, with not even a small light to brighten her path?
This is when it becomes an issue as to whether choir, and other worship ministries are for the mature to minister to the immature, (and mature, of course) or whether choir can be considered an outreach ministry. I've been in churches that have felt one or the other was the right definition. But the ones who felt that music had to be only for the strong, upright Christians never saw a single soul saved. I was in a Southern Baptist Church, where outreach was the motive, and the pastor went into the schools and found some young men who were willing to come and play various instruments, for free, who were far from saved.
Well, eventually most of those young men got saved. One even went into full time ministry. But the pastor was a bit discerning, too. One individual was dedicated to the music, but not to Christ. He was leading a very sinful life, and despite numerous talks with the pastor, and other worship team members, he did not turn his life over to Christ (ie repent!). So the pastor asked him to leave, and that was that.
But far beyond that, I am hearing about a troubled young woman, looking for attention on FB and social media with her off colour and rude remarks. This young person is NOT beyond the reach of God. She needs godly people to walk with her. Could your mother mentor her? Walk with her? Show her the way a Christian is before God? And more importantly, lead her to Christ? She probably is not a Christian, maybe doesn't even understand what it means to be a Christian. She is acting out, outside of church, in a way that suggests she is lonely, depressed, maybe has a bad home life, has been abused, and is very immature.
But throwing her out of the choir is the worst way to handle this. Can you not become her friend? Or are you afraid or what people in the world will say about you, hanging out with such a sinner? Because Jesus hung out with all kinds of sinners, from tax collectors, to prostitutes, to someone who betrayed him. He was mocked by the Pharisees and the scribes, who figured a holy man would separate himself from evil.
"And the scribes of the Pharisees, when they saw that he was eating with sinners and tax collectors, said to his disciples, “Why does he eat with tax collectors and sinners? And when Jesus heard it, he said to them, “Those who are well have no need of a physician, but those who are sick. I came not to call the righteous, but sinners.” Mark 2:17
Is the OP going to sit with a sinner, because Jesus is calling this lost girl, or are you going to stand back with the Pharisees and judge her? Because God will take no joy over this girl being cast from the choir and probably church and definitely him. Instead, he will take joy over a repentant sinner, and we need to be the ones reaching out to them. And in your case, the girl who does not know God, and may make you look like a sinner too, just by being with her.
"Just so, I tell you, there will be more joy in heaven over one sinner who repents than over ninety-nine righteous persons who need no repentance." Luke 15:7
I think you are right to be concerned about this young person singing in the choir whose life does not match what she is singing. But that concern has to be over the fact that she is not saved, does not know how to live for God, instead of worrying about "What will people say/think!" Please be a part of the solution and become a friend, and come to know the joy that the angels know, when you share the saving grace of Jesus Christ, this person repents and turns to God!
