<human>: Can you condense the text into three sentences or less?

so i told my friend i would post this for her. she has a pair of kitties who are brother and sister. liza, the girl kitty, has always had the same issue - i'm going to venture that the kitties are about 5 years old - of peeing in the sink. it's mostly in the bathroom sink. it completely rusted and disgustified their drain in their old sink so they replaced the sink, and since then she's still done it. if there is cardboard left out, anywhere, she'll pee on that (they just got a kitty emery board and it was peed on), if they leave one particular closet open, she'll pee in it. my friend just had to throw out two pairs of shoes due to cat pee. she'll also pee on any laundry left out in a basket. she's also been known to pee on guests' purses. 

they have spoken with their vet about the issue and he has no ideas. they've changed the type of litter, tried two litter boxes, moved the litter box to a different location, they tried some scent coverup stuff, even pepper in the sink. you name it, they've tried it. she still pees. 

they love their cat so much and will deal with it because they're devoted cat parents, but they are certainly tired of it. i did suggest that they get a second opinion from a different vet, but i also promised her i'd ask /r/cats! so pllleeeaaase, if you have any suggestions, she's game on trying anything!
<bot>: girl kitty pees everywhere (particularly the bathroom sink) and they've tried every suggestion in the book - help!