I think you are being both a little harsh and a little impractical. When faced with a sheer chiffon(?) top Victoria placed her sash underneath it, whereas Sofia moved the brooch down to the top of the satin(?) to anchor it.
Pinning a sash let alone an even heavier brooch to such fragile material merely makes it pull and sag. Sofia took a leaf from her sister-in-law's book and worked outside the box. On the other plus side, her order is perfectly placed.
I love the sheer femininity of this gown with its quite surprising volume in the skirt. Colours such as this focus us on the person and for kudos for wearing such a lovely maternity evening gown for only her second "big night out'. I have to admit I was a little iffy about the chiffon and beaded top, but a full-length look shows how both elegant and dainty the gown looks on her.
I'd call this a win. Far better than last year and she looks far more self-confident. She's learning fast and acquiting herself well.
If you closely look at that pic in the photo LadyFinn linked, it appears that the brooch is pinned (or could, and should, have been, IMO) to the heavier taffeta part of her dress and not to the sheer bit. The sash doesn't seem to be sagging and it therefore appears - to me, anyway - that the pin was not put in the centre of the sash but to the right side. I suppose it could be an optical illusion, but I don't think so.
She is doing well. Good choice in dress imo given she is pregnant.
