One of my dogs loves to do the same thing (pine cones are his other favorite). He, likewise, also likes to play chase. He knows I don't like him chewing those things, so he will do it to get my attention so I chase him. I have watched him closely and he spits out anything he chews off, so I have started to ignore when he does it. If I ignore him, he only chews on them for a minute or less. If she is actually eating anything she chews off and not spitting it out, I would definitely discourage it.