cat eating dog food

I recued a cat 'Motley' from my vets about 2 and a half weeks ago. she is coming along great. She now has heaps of confidence and is settling into the family very well...almost too well at times.
 
Our 3 dogs are free fed. They get kibble AM and then home cooked food PM. Motley the cat gets cat kibble AM and then raw or cooked PM. According to our vet, the cat needs nutrients that dogs dont and so the cta must eat cat food.
 
Anyway, we have been feeding her raw or cooked "all natural cat mince with added vitamins". There is beef, chicken, kangaroo all different sorts. She seems to like it too, until yesterday.
 
The dogs get human grade: mince (either chicken, beef, pork, lamb) or turkey pieces or saussages or fish or steak (maybe once a week they get organs) with either pasta or rice and veggies such as carrots, peas, punpkin, asparagus, tomatoe. I also add garlic sometimes and they get a pet vitamin in there a couple of times a week.
 
Anyway, yesterday the dogs were at daycare so I was putting their food down for when they came in and the next minute i see the cat eating from one of the bowls. I thought....ok lets leave her i dont want to startle her.
 
Tonight, they dogs havn't touched their dinner (they dont usually eat until they are ready) and Motley goes over and eats from their bowls again....while the dogs are watching [sm=eek.gif]. Sasha my rottie x kinda gave her a weird look but the others didnt care.
 
So yeaterday and today she hasn't had any cat kibble or cat food at all.
Is it ok for her to eat the dogs food? And how can i prevent her from eating it if it isnt ok?
 
Thanks guys