I usually explore the school while she's inside electrical and wait for her to get out. I didn't know cams changed color that's nice to know. Also you can bait her out by inputting a random password on the keypad in spawn.
So as far as I can tell she doesn't actually use the cameras. She can, however, tell when you are watching her on them. If she catches you on them, she will sprint to the security room. If you don't use them, it doesn't seem to affect the player. The cameras turning green is a bit more useful in my opinion.