Ouch, I have fewer allies in this discuss than I'd hoped. But yay, two pages of discussion pointing out that I was being selfish
I vote that I was completely justified (of course). As far as I could figure out, she was standing probably five feet away from the light switch in question. In order for me to turn the light out, she'd actually have to get out of the way. And in the time it would have taken me to get over there, she could have turned it out herself. The thing she was carrying must not have been heavy or cumbersome at all, otherwise, she would have told me to fetch it for her. I get annoyed when people ask me to perform an easy task they can do themselves when I'm doing something that requires constant attention, even if I'm just playing a game. I also get annoyed when people ask me to do an easy task that I could do myself without any help. She's pulled a few stunts like this before too. A long while back, she asked me to get her a pen (she, dad, and I were all the kitchen), despite the fact that dad was standing right next to the pen drawer, and I was on the opposite side of the kitchen. Dad simply gave her a look and got a pen from the drawer. She has also asked me to get her the remote when all she had to do was sit up to get it. I've been convinced for a long time that she instinctively finds asinine tasks for me to do when I'm playing games, as if she thinks that virtually any time I spend entertaining myself is better spent getting her stuff from the pantry.