first rule out no urinary problems so you may need to consult a vet.
it could be jealousy or she may like the feel of the dogs bed to pee in (some cats do it on human beds aswell
![Shifty :shify:](https://www.purrsinourhearts.co.uk/Smileys/purrs smilies/shifty.gif)
)
Wash and dry & spray/wipe bed with surgical spirits & i'd highly recommend feliway spray and ultimately if you could keep her away from the bed that would be best to break the habit cycle.