Yes, you should be very concerned. I am surprised Molli has not ended up with a bleeding mouth or serious digestive problems from the sharp thorns. The sharp pieces could also get lodged in her gums and cause a dental emergency, as happened to another member's pup with the little stalk of a green bean.
We have tons of sweet gum in Virginia, including a few in our yard. I rake up the prickly seed balls regularly and throw them in the trash. When we encounter the seed pods on our walks, I say "sticky balls!" and the dogs jump back to the sidewalk. I don't want them to injure their paws walking on them.
__________________ Kristin, Max and Teddy  |