What do you mean? Have you unlocked the repeatable photo shoots yet? Is there a bug preventing you to make money while doing them?
I've been to the photo studio with the girls and I never got money for it maybe it is a bug
Go to the photo studio while in free roam, if there are options to call the girls in, use those. If there aren't, you haven't progressed enough in the story, follow the instructions in the notebook.
