The hat looks extremely similar to a powder box my Granny used to have on her dresser about 40/50 years ago. Satin boxy and with a little bow. It was long empty of the powder, but my Granny loved the satin box (was given to her during the war for some anniversary) and my sis and I always put the two pieces on our hat to play "ladies". We looked JUST like Kate.
The hairstyle is great. And so very simple: you pull the hair into a low ponytail, twist it over once and then you stuff everything into the hairnet. Voila: done and oh so very stylish...not
Re. No. 2: right. And if/when she once decides to cut her hair, she can stuff the cuts into that hair net permanently and every time she needs an "updo", she can just pin the hair net into her neck, cover the whole mess with a silly pincushion hat and ... voilą: DM will go crazy about the new invention, KateNetBun.
By then mice will have nested in it, and the sight of them squirming around and poking their cute little pink noses out of the holes in the net will add an extra element of interest.
Don't mind me. I had a strange sense of humour that tends to surface late at night or in the morning before I've had my second cup of tea, though I certainly think that hair-netted bun would benefit from mice. They could be champagne-coloured mice to match the outfit.