I have read in other threads that a walking foot is not recommended for a featherweight. A quick Google turned up plenty of sites that sell a short-shank walking foot to fit a featherweight, but further Googling indicates there are problems getting these generic type feet to work properly on a featherweight (they seem to not feed the fabric evenly between top and bottom). There was a walking foot specifically designed for featherweights called the "black penguin" or something like that -- apparently because of its height and color -- but they are very rare and very expensive if you do happen to find one.
Just found a reference to a Singer low-shank walking foot that works on a featherweight ("smooth and even-feed walking foot"). Apparently the Clotilde deluxe low-shank walking foot does not work; the foot does not line up properly with the feed dogs.