How does one know if a photographer for models is legitimate or a fraud?

My step-daughter is interested in modeling. Her mother took her to a photo shoot with a photographer who said he was a professional with connections to modeling agencies that dealt with commercial modeling work. My step-daughter is a gorgeous young lady—she photographs well, but her dad and I are concerned about her being exploited. He doesn’t feel his ex wife is knowledgeable or cautious enough to make the best decisions regarding modeling. Instead of wondering, I decided to ask the collective—

How do I know that a photographer is legitimate and won’t lead her into the underbelly of the modeling industry? What things should we be looking for to protect her and make sure she’s getting real access and is not being taken advantage of? What are some red flags?