"Next, ask yourself why the P-vine is forgetting stuff. Does she have too many things to do? Does she have to move on to job no. 2 before she can finish job no. 1?


crazy little woman is onto it... You have said almost NOTHING about what P-vine has said about her problem if & when you two have 'discussed' it. Does she have a real problem with memory? or does she think it is actually up to YOU to cleanup... that makes 2 entirely different problems.
If she has a problem remembering to clean up her stuff, is there any way to have a reminder system? A card hanging on the door knob saying "Bring in the tools"..or whatever.

If she doesn't FEEL responsible, you have very few options.