For tandem use, go with the 36 inch bags Posted by: g2d on Feb-07-13 2:55 PM (EST)
Your wife might need to slide her feet a bit under the front bag when sitting. Often you can work out this sort of thing by laying out the bag, seat, and person layout on a picture of your canoe from above, which you can capture from their website. Just the usual right click and save as steps, then print the picture.