Neighbor helps herself from my garden

I live in a 55-and-older mobile home park, and while my home isn’t large, I’m fortunate to have a small but lovely backyard. I’ve made the most of it by planting a little vegetable garden and caring for a beautiful lemon tree that brings me a lot of joy.

Recently, while I was tending my garden, a neighbor who lives behind me stopped by to chat. She admired my vegetables, but when she noticed my Swiss chard, she exclaimed, “Oh, I’ll have to pick some — my daughter loves it!” I was stunned. She didn’t ask if she could have any — she simply announced she would.

To make matters worse, she’s already helped herself to lemons from my tree. I actually caught her doing it once, but I was so surprised, I didn’t say anything.

She has the space to plant her own garden but hasn’t made the effort. I’m not trying to be unfriendly, but it bothers me that she feels entitled to take from mine without asking. There are no fences between our yards (yet), but I still feel like there should be some boundaries — literally and figuratively.

How can I address this politely but firmly, without causing tension in our community?

— Not a Free Produce Stand