It might be a good idea if you can feed the cats and the dog separately, and lift up the cat's dish when he has finished eating, so greedy doggy doesn't get in there. Or feed them in separate rooms, with a closed door between them.
If your dog is being fussy, then leave her food down for maximum 10 minutes (during which time she either decides to eat or go without) if the food is not eaten, up comes the dish,....and no more till the next mealtime. Believe me, she will soon get the message, and will not starve herself to death.
OK you have to be strict here.
I have never known a normal healthy dog who will willingly starve itself to death, so hang on to what's right and don't weaken, no matter what the "pressures" from her!.
Dogs should not eat cat food.Bad idea. It is too rich for them and contains Taurine which their digestion can't handle.
Dogs should not be fed table scraps. Even if they are in the process of convincing you that is all they can stomach....it is not true. Human food contains all sorts of bad things for dogs salt, seasonings, pepper, fat, unsuitable carbohydrates....etc, and will never fulfil their nutritional requirements.
They need a well balanced, healthy dog food. And water. Possibly some home cooked meat, fish or vegetables to go with the dry food. No seasonings, no salt. Just plain cooked meat or fish with a small amount of vegetables which are suitable for dogs. That's it. They don't need dairy, they don't need anything else.
So get to it, and do what you know is the best thing. And don't let that little dog of yours tell you what she will and will not eat. If you pander to her, it may not be very long before you will have a sick, overweight dog.