A couple of days ago we looked out our window and saw that our next-door neighbor was mowing our lawn. We have noticed her lack of interpersonal boundaries on several occasions since we moved in a couple of years ago, but it hasn't outweighed the positives of being neighbors – until now. Anyway, my husband went outside and asked her what she was doing, and her reply was a mixture of concern about leaves blowing onto her lawn and wanting to do us a favor because we are such helpful and good neighbors to her.
There were leaves in one distinct area of our front lawn close to her house, and we were on our way out to run some errands, so we shortsightedly shrugged it off and went on with our day. While we were gone she proceeded to mow our entire front lawn and the public right-of-way that extends around our property (we live on a corner lot), and she mowed it much shorter(*) than we customarily mow it.
Since the lawn care in our household is my domain more so than my husband's, I am volunteering to have “the talk” with her. The issues as I see them are as follows. She came onto our property and started altering it without our prior knowledge or permission and she preempted our agency and willingness to remedy something that she found problematic. She then corrected the problem far beyond the scope of what she had indicated to my husband and did it to her own aesthetic preferences rather than ours. There is another issue worth considering: the possibility of her injuring herself while on our property and our liability in that event. https://injury.findlaw.com/accident-injury-law/premises-liability-who-is-responsible.html
People with poor boundaries often don't take hints easily, so I want to be direct but not unnecessarily harsh. I'm looking for suggestions to prepare myself so that I can say what I need to say, and suggestions on how to handle what I imagine will be defensive or deflective responses on her part. I think one opening she might use is the fact that my husband didn’t explicitly tell her not to do it, and she would have naturally assumed that he was speaking for both of us.
(*) We mow our lawn to about three inches, and mow it once a week during the growing season, so it is never anywhere near nuisance height. I had last mowed it in mid-November, and although we have had an unusually mild fall, it has not grown appreciably since then.