I couldn't find a link to your photo so I don't know what your scarf-dickey looks like. Since feather-and-fan is a lace stitch, however, I would guess that you are accidentally adding extra yarnovers. That would explain why the scarf kept getting wider instead of remaining the same width throughout.
A lot of people over-think yarnovers and end up making extra loops, which turn into extra stitches on the next row.
So listen to Mama: stop putting yourself down, learn the correct way to do yarnovers (it's easier than doing them wrong): http://www.knittinghelp.com/knitting...increase.phpyo
jhstop and don't tell anyone that your lace dickey was supposed to be a scarf.