I don't think the dress would have been appropriate for a funeral because of the sheer panels. Plus she has those frilly shoes on. The hat, oddly, strikes me as funereal. I don't like the outfit, though. I don't care for the way it fits, I think. It looks a little big on her. The jacket sleeves are bunchy, and that drives me crazy, so I just want to go up to her and pull everything straight. That satin skirt looks a little flimsy and clingy, so combined with the sheer panels in the bodice, the ensemble rather evokes lingerie. And personally I would have done more in the way of jewelry in the name of festivity. And lastly, the burgundy shoes and clutch are lovely, but they would have looked much better with a gray dress.
Anyway my point is that it doesn't look quite right, but not because of the no black dresses rule. It just isn't that great of an outfit.