This held true for the TV and film industry as well, and continues to be the subject of debate and negotiation. When people of color were employed, it was often the case that they portrayed stereotypical characters. It has taken a lot of sensitizing to break down some of the barriers. The notion that programs should reflect the community they serve carries over to who is pictured in publications. Photos should show that.
Budget can be a constraint.
You may be able to find a photographer willing to do some pro bono work or there may be a photographer on your board happy to help out. But finding the children to serve as models can be difficult. Some people, in and out of the field, may be uncomfortable having their child pose for photos for an organization concerned with abuse and neglect. Assuring them that you only use models, never children from real cases, may not alleviate their concern and of course, you must respect that. After you've used all the children of willing staff, your friends' children, and your relatives' children, you may be at a standstill.