Any toy poodle experts out there, what and how much should I feed her?

I have a toy poodle, she is seven years old (yes, I realize I've waited a while to ask this), and I know she is being fed way too much, I have told my mother over and over again to cut back the food, but she won't until she knows how to feed her. This dog is a whopping fourteen pounds, and I do take her for walks for exercise, but she is fed 3 times a day. In the morning, she has purina little bites dry food PLUS a spoonful of pedigree wet food. Then she has a handful of dry food in the middle of the day. Then dinner is the same as breakfast. PLUS she gets pupperoni dog treats throughout the day (about an average of two or three a day) and maybe once and a while a few pieces of dry food. I know this is a lot of info, but this poor dog needs to lose weight...I can't tell you how many times the vet has yelled at us. What good feeding habits should we put her on? Also what are good brands of dog food to feed her? Thanks so much!