It looks like she searched for "can I put a gun in my suitcase?" And for domestic US flights, having a gun in your checked baggage is normally allowed (altho you're supposed to lock the case and declare it).
I think she probably didn't realize other countries have different laws and didn't see a gun as anything special or dangerous. These are both common American viewpoints. I also wouldn't be shocked if she didn't know other countries could put you in jail. 😌