Right. Try feeding Bella twice a day. She is an adult dog. Many ppl only feed an adult dog once a day, so it's up to you, but I prefer breaking it into two meals to avoid gorging and bloating, amongst other things.
What she hasn't eaten at breakfast, put away. DO NOT LEAVE IT SIT AROUND.
Feed her again at night. Same rule applies. She will learn to eat her meals when you give them to her, as there is no more coming until the next mealtime.
As for the cats, yeah, start giving them cat food and put it somewhere Bella cannot eat it, obviously.