Originally Posted by catnapper
Did the vet actually test her urine or are you just assuming she's being a queen bee? The stress of her human dying and being relocated to a new home could be enought to bring on a major UTI or bout with crystals.
She might also not like the litter you're using. Is it the same thing your grandmom used? Are you sure? Some cats are very fussy.
How many litterboxes are around? With 6 cats, you need at least 7 boxes. I don't care that you said they are clean... to YOU they are clean, but to hershe can still smell where 5 other cats went, and she might want a box all her own where she can pee in one, poo in another. I have 5 cats and 7 lkitterboxes and those additional boxes made a HUGE difference on Allen peeing in the wrong place. Also make sure you have them spread throughout the hosue -- one upstairs, one downstairs, etc.
Also, have you tried different litter levels? Some cats like a lot of litter while other like just a little bit.
I agree with Donna too about it being in a high traffic area. The most used boxes in my hosue are ones that are secluded and hidden from human eyes.