Your daughter use more than one large can of Aqua Net Hairspray a day. Is that safe?

No. Every time she sprays she is inhaling chemicals and spreading them through the air around her that other people breathe. Take a look at the label for a list of those chemicals. She is overdoing it and you need to take action. If she doesn't outgrow this in a few weeks, you may want to engage a psychologist to figure out what's going on.