my wife was the same, she was bored out of her mind watching one piece.
so what i did was to make her watch one arc.
you pick: arlong arc or water 7 saga.
so i told her "just watch one arc, if you still dont like it i wont force you anymore"
i made her watch the water 7 arc - enies lobby arc first, after that she got hooked.
and she dropped fairy fail, realizing that there are better animes around.
and then we watched it from the beginning, because she became invested with luffy, ussop and she had a crush on zoro LOL
and maybe it helped that i agreed to watch fairy fail with her first (which is a torture.)