Love the plan Ana! I made a couple slight revisions and made mine out of all 2x material. I used 2x6 for the arms with a taper and extended the arms over the front leg by 1.5 inches and used 2x6 and 2x4 for the seat and back slats.
Boys it sits great!
One other thing I did is I used pocket holes and concealed all my fasteners so I don't have any screws showing.