I wouldn't be able to handle it if my own mother lived with me.
I don't know how you do it!
I agree a nice calm talk with DH might help. Or it might not and it might be best for your sanity to just allow her to do her laundry. I have this conversation with Dave about three times a week about his kids doing laundry every day. After weeks of fighting about it, we decided laundry can ONLY be done on Sunday and Wednesday

That way two or three peices of clothing aren't being washed alone.
Good luck...and vent away! I know I always feel better after typing things that bug me.