hmmm,well i guess she is a puppy??i had the same problem with Kodie and still do,but not as bad as your Maggie.When Kodie was in the bad stage we got him a shock collar which worked wonderful,but then it got wet so it doesnt work anymore. im not really an expert on how to fix those things,but oone thing i do know that might help is to say "NO!" in a loud,but stern voice.and only say it once.It works for Kodie when im working with him,and thats what the trainer tought me.

Hopefully someone else here has more suggestions then me!

btw- if she is a puppy,thats what most puppys do,chew everything they can get their teeth on,Both my RB dogs did that when they were a puppy,but got out of it.