Next time it comes up, you make sure to mention that you weren't happy, either.
The first time I said that to W it really threw her. It was almost like she was thinking to herself that she was perfect and all this unhappiness she was feeling was a direct result of me being there.
WWs blame the LBH for everything. They sincerely think that the LBH is the sole source of issues. She has no idea that she will run into the same host of issues with the OM down the line.
If you can tell her that you weren't happy and explain why, it can really make them reflect.
When I said that W instinctively went on the defensive. She said "how could you not be happy when I did X, and X and X for you?" my answer was that those weren't things I cared about. My LL are "X" and "X" and I haven't gotten those things from this relationship in a long time. I haven't felt loved for a long time...
Seriously, don't do anything now because it's too late, but if she tries to throw that in your face again, come back with that little truth dart and pop the bubble.