Get a neoprene sleeve (~$20) that's large enough to hold both the PW and its case. It adds bulk, but also a greater degree of protection. In order to work properly, she has to keep the PW inside the case it's already in. Then she needs to put that combo inside the neoprene sleeve before placing it inside her purse. Failure to use both layers of protection will more than likely result in another broken screen.
Keep in mind that this suggestion isn't foolproof. An object with a sharp corner can apply just the right about of force to defeat both layers. Also, a fall can still crack the glass substrate, even with both layers in place; although it's less likely to do so.
As always... YMMV
|