Am I rude?

I have never considered myself to be standoffish, or a hermit, or unsociable. But there's something that bugs me to no end, and it makes me wonder if I am just a little bit rude. Sometimes when Reed is playing outside, I come outside and sit on the patio and read. I figure that that's a clear signal that I'm reading--not up for talking, unless I initiate conversation, or if it's a short greeting. But there is that same person who doesn't seem to notice that I'm happily engrossed in my book, and that person always comes and tries to make conversation. I'm usually polite, responding with at least a chuckle or a "yeah". I simply sit in strained impatience until she leaves--fifteen minutes later. Perhaps she's lonely, but it happens every time I'm outside, even if there's someone else with whom she could talk. Which brings me to my two questions: Am I rude? Or do I need to be a little bit rude, just to establish that I don't prefer to talk when I'm reading? And that brings another question to mind: Is it bad that I sometimes go out on the patio with no intention to be social? I don't think going outside should come with a prerequisite of likability and enthralling conversation....but maybe I'm just being a little bristly? This little concern of mine extends beyond my little patio; small as this may seem, it makes me wonder if I sometimes go out into the world with the intention of being slightly repellent as a way of defense. I don't usually think of it that way, but sometimes I just don't feel that sociable, and don't want to pretend I am. Isn't it worse for me to pretend, rather than to just represent myself as I am? Definitely I'm overthinking this....