Like you, I afterschool my son. He knows that it is required if he wants to go to school (otherwise we'd homeschool). I have two categories of work that we do. One is conversational on the couch. For example, I read history and science stuff aloud. We are also reading Life of Fred aloud. That sort of thing. The other category is things that don't lend themselves well to a conversation on the couch. At the moment it is grammar. I'm having him go though an 8th grade grammar book (he is 5th grade age) because his school doesn't teach English (at all). I'm giving him a big reward when he finishes it, which won't be until sometime in the summer.
So, I guess one thing you might consider is to make the afterschooling stuff be time spent with you rather than on the computer. If it's math, use a small whiteboard and write for her--make it a conversation. I know that my son is much more inclined to do extra schoolwork if it's with me and not just computer stuff or a bunch of workbook pages.
