We bought a rental property a month ago, and we want to be friends with all the neighbors. But - a neighbor that borders our lot along the back line has been throwing her trash (large items) into our yard.  

While we don't have proof that whatever junk we saw came from her, even though other neighbors tell us so, we have evidence of the last "load" belonging to her. I was taking pictures during our survey last month and one of the photos captured this junk sitting on her yard. Last week it was thrown into ours, and even tore off one of the survey stake ribbons. 

Does anyone have advice on how to handle this peacefully? 

As a Plan B - I would involve Code Enforcement Office. I already consulted with them and they can help, but this certainly wouldn't help establishing good relationships with this neighbor. 

Are there any other methods? 

The neighbors describe this lady being in her 40s and quite aggressive/confrontational. So, we expect our interaction to be difficult. For now my husband and I are thinking to visit her and ask her to clean up the last load of trash. We can even offer her to use our dumpster. If she doesn't open the door, we thought we'd leave a polite note with the same request and a deadline. If nothing is cleaned up by the deadline - then we call Code Enforcement. Does this plan sound reasonable?

Below are some photos. The first one was taken during survey and on the far right side you can see the junk on her yard, which later migrated to our lot. The other two photos were taken last week. 

Thank you!