OMG, I just realized I completely missed this, Joy. I'll PM you too.
I do think it would look great over the kind of dress you describe. I feel like this jacket is cut quite generously, even for EF. I have a feeling it might be roomy on you, unless you layer it over some bulkier pieces.
I need to add photos too. Must do that today. I admit, I forgot about this listing until I ran across the jacket during my closet and holding zone review.