Let her keep a little purse in her backpack for her to take with her to the bathroom. SHe can keep a pantyliner/pad init as well as other stuff as not to make it obvious, like a small pack of tissues, chapstick/lip gloss, small body spray, compact mirror. My daughter uses a dark colored, small make-up purse. She has pantyliners (not heavy enough yet to use pads), lip gloss, small packets of tissues and oil blot sheets in hers. She keeps it in her side compartment of her back pack with a small bottle of water. She doesn't have lockers and they change classes every period and the backpack goes with them to every class.