What should I do about this friend?

There is this girl I have hung out with since we started school (about 2 months). Well, we don’t really even hang out, she just texts me so that I can eat with her at mealtimes. I don’t want to spend any time with her, really. She depresses me and annoys me because all she does is complain about things when we eat together. Our conversations really have no substance. I know that she doesn’t like to eat alone (whereas I don’t care if I do) and she’s told me before that I’m her only friend. She’s nice, sure, but I just don’t want to eat with her or anything. I don’t want to be mean to her, though. I just want to know what I can do about this kid. We have a class together and do some volunteer stuff in the same group. How can I make it so that I can see as little of her as possible? (And yes,I know I’m being a wimp by not being upfront, but I can’t help it!)