Because you didn't address public domain/royalty-free pictures in your clarification, others might still question it. Pictures from a public domane or that are royalty-free are fine to use in such cases. Generally, such pictures don't include pictures of boys, unless they are purchased from a royalty-free stock exchange (and some exchanges sell royalty -free pictures of boys for credits costing a dollar, ie: istockphoto). So in such cases, it is ok to use those pictures.

Be careful with royalty-free, make sure the license allows you to let others (i.e. cblf) use the image in perpetuity also. Many royalty-free licenses only apply to YOUR use and in some cases specifically exclude making electronic versions available outside your home or business (e.g. clip-art that has royalty-free printing rights). In other words, to be legal, CBLF would need to license the image.

Public domain is another matter entirely, those require no permission.

I don't recall the CBLF rules, but BoyChat doesn't allow people unless it's you.