Hi Julie, thanks for bumping your thread so that more people could answer. I highly recommend this resource:
http://www.pfaf.org/user/plantsearch.aspx
You can do a search for a shade tolerant tree or shrub with high edibility rating in your zone. I did a quick search for zone 6 and it said that there were varieties of pears, plums, peaches, cherries and many berries among other things that will thrive in full or partial shade where you are. You might also want to look at edible climbers.