Litter box

So one of the kittens won't always use the litter box. They're 8 weeks old today. I know which one it is. She will pee on the bed. If I leave her in a room with the box she'll use it, but she will pee where ever if she's not locked in the room.

How can I fix this. She's the only one who does it. 

I have the same problem with my 7 wk old kitten when shr is locked up with her bix she uses it but when she is out she doesnt use it at all. I rly need help bc my hubby said I will have get find her another home if she dorsnt start using the box. Please help us!!

For kittens, I'd suggest putting them in a small room, like a bathroom.. sometimes they need help finding their litterbox. Being confined in a small area close to the box may help teach them how to use the box properly.

Just in case, check with the vet.. just to rule out any health issues