If you have a mother infected, it might be a good idea to separate the baby chicks and place in brooder in the off chance they did not get infected by the adults but again maybe call vet and get advice quickly.
Here is resource that reviews fowl pox well. I would follow these treatment guidelines http://www.poultrydvm.com/condition/fowl-pox
Need to isolate sick birds. Have access to clean food/water. See vet. Vaccine may be available to protect birds. May want to consider since more new ones coming...