Legally you don't need to give permission if you post photos to Facebook- online. any third party can legally take and use them without your knowledge and not have to pay you if you post photos online. Because you post them online it's public property. Even says that about Facebook photos

You are half correct. If your image is being used and they're making money off it (They would be as its used to recruit) She can ask to take it down. But what a lot of people don't know is when you sign up for colleges/universities, some of the papers you sign give away your rights to claim photos taken on their property or during their events. Since it was (i'm assuming) the graduation taken at the school, she has no right to it. (Again, if she had signed the paperwork stating the school can use photos as they see fit) Did the school hire photographers to take photos of the event, and it was someone the school hired? It's the schools photo on their own private property. It may cost money to have it removed, or perhaps she could just write a well-worded letter asking to remove or receive a monetary credit.

I was redundant with the "Someone a school hired sentence" I really wish I could edit again. :\

Maybe on Facebook, but if you post photos online, it does not give people the legal right to use them in any way, especially commercially. For example, big company websites are plastered with their logo, it does not mean you can use their logo or images if you want to advertize your own thing. Like lets say it is a wrist watch company, you can not take a picture of their model wearing the watch and then use it to advertise something like "Our Resume Writers are here for you just in time" and advertize your resume writing website. People can and will steal images, but it is not legal. You can be sued. Different websites will sometimes include in their ToS that they can own or use your images, it depends where you post them.