How private is too private?

I'm a private person. It seems to get worse the older I get. I'm not terribly interesting nor do I have anything to hide but I still don't like for people to know anything outside of what I want them to know. In other words, I guess, I want to be the one who tells people things so that I can decide who and what. I have a very close relative who tells anything and everything she knows about me to anyone and everyone she knows. I've asked her not to do this, repeatedly. Yesterday, I found out that she's driving her friends (not my friends) by my house to show them where I live. I feel that this is unnecessary. I'm not afraid of them, I don't think they will do me any harm but I don't like it anyway. I guess it mostly bothers me because I've asked her to keep stuff about me to herself and clearly she's not going to do that. Note that I am in very close proximity to this relative so her not knowing stuff about me isn't an option, she will know at least some stuff simply through proximity. I've stopped actually telling her very much but she gets mad because I don't share with her. When you have nothing to hide, does wanting privacy make you a jerk?

(I have some health issues and I just don't want people knowing about them. She says she tells people so they can "pray for me" but that really just feels like her trying to legitimize not being able to keep things to herself.)