She might be entering the terrible teens and feeling rebellious. .The only thing I can suggest is if there is anyway to attach the litterbox to the side of her cage so that she can't tip it out and maybe giveher a few toys or blankets.
If she goes outside her litter box, just pick up the poop and put itback in and soak up the pee with a paper towel and put that in thelitter box. Spaying helps also with litter box habits.
Also, see if you can keep the litterbox in place by attaching it tocage wire or weighing it down so she can't throw it around, and giveher some new toys to play with instead.