get a male? i believe they get much smaller than the females. i believe 6 ft in full grown for a male but obviously it can differ. if you're getting an aquarium set up (which obviously sucks for controlling temps and humidity) but with the lids with locks it is an easy way to keep your grandma from worrying. also stacking books works i've heard but obviously much less reliable. if i were you i'd try to impress her with your knowledge and research you've done on rtbs and also on possible setups. i would doubt an escape if you get a lock and also stores sell extra locks or use heavy duty clips.