Are there laws against a school social worker discussing parents financial state with students without parent?

Someone had left a check donation for my injured 22 yr old son with a social worker at my 12 yr old's last school. She called me, and I told her about the bad financial situation we are in due to his injury. She called his new school, and the social worker there gave him a form requesting Christmas assistance. That would be ok, but she didn't put it in an envelope, and she told him that it was a form to get him presents if we were having financial troubles. I called her saying she had no right to indicate to my 12 yr old that we were having financial troubles, and she argued with me saying she always does it that way. There has to be privacy laws against this, but I can't find them. Can anyone tell me plz so my letter to the principal will be correct. Thank you