Do I need a reference for every subject?Watch
Usually this will include comments on each of your subjects. If you’re taking an A level privately then speak to your school about who will write your reference. Ask them to explain that your exam centre isn’t able to provide any details about your studies within your reference. That will also explain why there’s no predicted grade provided for psychology too. Your school referee might be happy to add in a short sentence about what you’re enjoying about psychology based on a conversation with you.
Universities will understand.