The Bible teaches that a leader in the church must first take good care of their own family (1 Timothy 3:5). If anyone cannot manage their family, how can they manage God's church? I think that the same principle applies to helping children involved in sex trafficking.
All children are certainly God's children. While we are responsible to care for every child that we can possibly help, God expects families to provide for the children entursted to their primary care. Sadly, it is not uncommon for well-meaning people to neglect their families while campaigning and working on behalf of other children in dire circumstances, both domestically and internationally.
I don't think that it has to be an either/or situation, i.e. either we help our kids or we help other kids. It can certainly be a both/and. We can love both our children and the children of the world. Yet, we are to start with the children God has entrusted to us. If we cannot take care of our own kids, how can we be trusted to take care of others?
This principle is not limited to parents. Grandparents, aunts, uncles, godparents, friends, neighbors, church family...who are the children in our everyday lives? How are we loving and protecting them?