Can I request a tourist visa for a family member that is a US Citizen in China Embassy of Costa Rica

I am about to travel from Honduras to Costa Rica to get one for a 6 day tourist visit to mainland, for members of my family and myself. Two family members are US Citizens and five are Honduras citizens. I want to know if I it is allowed for me to represent all of them in your embassy in San Jose, Costa Rica. I would be taking their Passports, request forms, and documents with me. Please confirm.