Annoying neighbors help

So we have some great neighbors and one that is "strange" we have had some very bad interactions with this neighbors but we try to still keep friendly. They are directly across the street and in distance the closets we all have lots of land and woods. This neighbor doesn't understand boundaries and we don't feel comfortable with them on our land. We've also been warned by other neighbors as they have issues with them and have found them in their garage and home and they were not invited into those spaces.

The problem is this neighbor keeps asking to harvest plants off my land that grow naturally. I don't have window coverings and I have caught her looking in my window one morning to "drop off something" when I already told her not to and I was pumping nursing and topless. I don't trust this person to not be snoopy or really want her to feel comfortable coming over. I also don't think she is a malice person I just don't care for her and her gossip. How do I keep telling her no that I don't want her in my woods.