Large leafed mystery plant
This is a non-native tree known as Empress tree ( Pawlonia tomentosa). It was originally brought into the country because the wood can be valuable, but it grows so fast here that the wood is weak and worth nothing. And, it turned out to be invasive. So, unfortunately, we can only recommend that your neighbor cut it down as soon as possible. It gets very large with weak wood, and the flower smell can be quite unpleasant.
Thanks for your quick reply. I thought the leaves looked like a Pawlonia, but it didn't occur to me it might be a seedling. I'm a Montgomery County MG and we really appreciate this service. Keep up the good work!