Yes they are definitely fun for them! =] I hang mine up and my two like to play "volley ball" with theirs together HAHA. Especially if there is a tasty treat to lick she most likely won't think about chewing. They also have this toy called a "pacifier" where you mount it onto your horse's stall wall and they can take their lips and roll around on it for fun. I haven't tried it yet, but I'm going to get one and do so. They also have sprays on the market to put on the area they chew on that tastes bitter and repels/discourages them from chewing. Good luck!BTW, if it gets worse, they have cribbing collars with sheepskin lining that you can use on her to stop the cribbing/wind sucking.
More hay would be the first thing I would try, doesn't have to be the best hay, such as alfalfa, but something to keep her busy.
Horse's either love the jolly balls and lik-it's or could care a less. We used to have the lik-it's that hung from the ceiling, they never touched them. Then we got the ones that mount on the wall and they have to spin them to get to the lik-it..... BIG fun! Keeps them busy for a long time.
An old milk jug with some hole punched in it with a bit of grain may hold her interest.