The French were strong up front and put Wales under a lot of pressure which they converted to points in the second half as they added a further three tries to the board.
Wales finished fourth, ahead of Spain and Ireland, having displayed some superb rugby over the seven-week tournament. They recorded a 34-0 win over Spain in the opening game at the Cardiff Arms Park and last week beat Ireland 17-0 in another convincing win.
They were unlucky in Scotland to lose 9-8 after being 8-0 up at half time, thanks to a superb try by winger Hayley Baxter, who has shone in this season's competition.
England won the Grand Slam after beating Ireland 46-3 in Limerick on Friday night.