Food stamp recipient claims question!?!?

I’m trying to figure out if anyone can help out with a question. My friend had food stamps and was working as a PRN at a job she got a new job with a temp service and told the food stamp office about it apparently whoever she spoke to said they would send out paperwork for her to bring back with her paycheck stubs since she got paid every week she was going to turn everything in when she got a full check. she never received anything in the mail to turn information in then which this isn’t the first time that has happened. Then she got a letter about Food stamp recipient claims and needing to come in for a face to face because they think she received more benefits then she should have. I’m not sure how this all works can someone give a insight on what exactly is going to happen? Thank in advance