Not sure what to call this, this cat ive had her and her brother since they were kittens.

In the last year or so ive had issues with her, just her. He doesnt do it, where she will use the bathroom out of the litter box, ive tried different litter boxes, etc thinking she couldnt get in the ones we had cause shes a little chunky.

Nothing. She will mostly use it but will still find where shes used it elsewhere. Put a new litter box out yesterday. And shes proceeded to pee at the lip so it goes in the floor.

I am at my wits end. I dont know what to do with her.