B.M.
Hi J.,
Chewing can give us a soothing response. It is why we chew gum. Why adults use food to soothe themselves. Why one might crave chips verses yogurt. The act of chewing on things, at your daughter's age is a self-soothing behavior that has become an unexceptable habit. Many children do this. I work with many kids older than 5 who still chew on their fingers and hands. The key is to find something else for her to physically do that will take the place of this behavior for awhile until it is no longer needed. Whenever you attempt to change a habit, be prepared for a struggle. It isn't easy for any of us to change our ways. You could try to give her something to hold that moves such as a stress ball or a small plastic/rubber object that twists and turns. Whenever you catch her putting an object in her mouth kindly say, "Remember, use your hands, WE don't chew on things." You could also try having very crunchy snacks throughout the day, such as carrots, granola, apples, and have her brush her teeth many times a day. Maybe all of that extra stimulation will help a little. You could tell her that those things will help her mouth feel better so she won't need to chew on things.
Good luck. This will be a challenge, but you will both get through it. :)
This will take some work, but try to stay calm and kind