I'm guessing you already asked her point blank "why do you let your dog shit in my yard?" What did she say?

Can you put a lock on your gate so she can't open it?

We had a mean neighbor with a mean dog once. This dog would dig under the fence and try to get our rabbit...he finally killed the rabbit when we weren't home. The neighbor didn't see a problem with a dog killing a pet rabbit. He said dogs do that. so.....

We had a very large bag of potatoes from our garden...and every time the neighbor was gone my husband would throw potatoes at the dog and make this funny noise tee yow! tee yow! They were small potatoes but bigger than a marble so I am sure each one stung when it hit. My hubby kept it up for about 3 days and then all he would have to do is make the noise and the bunny murderer ran in terror...

It was really funny one night when they were having a BBQ. They had all these friends over and they were standing around gloating over their big fat dog and my husband just barely whispered tee yow out the window and that stupid dog put his tail between his legs and ran into his house and they could not get him to come out...I laughed so hard.