I think Muslims need to understand that helping the poor is a part of the Christian living. So of course, they identify a need and commit their lives and goods to helping the needy. In the process, out of curiousity people ask about our faith and we tell them we are Christians. No one is forced to convert.
Another point Muslims need to understand is that God calls people into specific areas. Christians don't go around to promote a religion. We go where God sends us to go. We don't just do some religious dos and donts and call it inshaallah. We first determine what is inshaallah through our prayers, and then follow as the Spirit leads.
Example: there was a time when the Holy Spirit prevented Paul from preaching and also from going to a certain area. Later in a dream he was called to go to Philippi, and found the first European convert there. (Acts 16:6-9).
So if God is showing love and mercy to the children through these organisations, why is there so much fuss?