I'm not a Windows 8 expert but I do like all your networking questions on this board, William!

A couple of things I always do when debugging these kinds of issues:
1. Plug in to a hardwired network to eliminate any wireless issues. You don't *have* to do this but networking issues are complex enough to warrant eliminating some layers that could contribute transient issues.
2. Try things both ways. Can your partner access files on your machine?

BTW, with Windows 8 where are these files that you are trying to access? Are they in the generic shared folder or did you share a specific folder? Also, I am kind of assuming that you are using Guest sharing and not sharing using a userid on the remote computer, right?

Which edition of Windows 8 is it? Basic or Pro? I assume it isn't Enterprise.