Flying leaves

California
Four years ago, our neighbor took us to court because some of the leaves of our trees were falling in her swimming pool, thus, according to her, rendering the area unusable. She claimed that this has caused her and her family undue emotional and psychological stress, they can no longer use the pool, entertain friends, etc. At the time, the neighbor's daughter had just passed ther bar exam, and since we had been sued for one million dollars, we hired a lawyer to represent us. After a $10,000.00 legal fee, we had a gardener trim the trees, and had him go to their property to remove the leaves.

Just two days ago, after enduring winds in our area (Sou. California) of nearly 60 mph, the lawyer next door called us to tell us that once again the leaves from our trees had fallen in her backyard. Since we obviously do not want to go back to court, are there any laws that protect us from this ridiculous and unreasonable demand by our neighbor, any previous court decisions that we could cite to help us in this matter?

Your input would be greatly appreciated.