That's a setup problem.
The tongue rotates in a pair of clamps, like muffler clamps. You can kinda sorta see them in the photo of mine. You're supposed to rotate the tongue so that the trailer is level, then slide it left or right so the trailer tracks centered behind the bike. Finally, you need to rotate the hitch on the bike so that it pulls level as well.
Those three little steps seem to have been neglected on her rig.
It just looks like all the books are ready to fall off the shelves with it like that.