Hi K., This may be a duplicate because I thought I sent it earlier.
My daughter was also a chewer although it wasn't centered around her bed. You are very right to be concerned about her choking and I wouldn't wait to let her just grow out of it. I do know that some kids are more orally focused even to a later stage in life. My daughter at 14 or so still had pen caps or bits of plastic mulling around her mouth. Surprisingly she is not a gum chewer. I do believe it is behavioral and this focus on her bed items is unusual enough to talk to a child therapist that has experience with early childhood development.
My daughter is now 16 and has braces. She takes the rules about braces seriously and I think this has helped and may move her finally past this need for oral gratification. Children are all so different and one of best tools we have as parents is to follow our gut feeling.
You are doing the right thing by reaching out. Keep going until there is an explanation and solution. Keep going and demanding help until you can sleep at night in peace. Lastly keep being that caring mommy who will fight hard to do what is right for her child.
Best of luck,
H.