I really wouldn't worry too much, some children need to work through oral stimulation more than others. Try to find things that you don't mind her chewing and are safe. You could get her to help you decide what would be appropriate, safe and satifying to chew? Remember it is perfectly normal and she will grow out of it. Stay positive, guide her to the things she can chew rather than criticising her.
P.S my son age 6yrs chew everything too, but I remember chewing pens and pencils at school, when I was young. I have met loads of children who eat their clothes, (chew on sleves etc). Pease don't worry. Give her a cuddle and tell her you love her the way she is.
I just did a search and found this message and am amazed because my 5 year old is the same. She is also very confident and happy and aswell loves to fiddle and can't sit still (loves stimulation).
We have just given her a baby blanket to chew on at preschool and with the help of her teachers are encouraging her to only chew on that with the understanding that this will be taken off her in time when she learns to stop the habit.
Not sure if it will work but are giving it a try anyway.