Very elegant and appropriate
She looks lovely and very emotional.
This outfit is perfection. I didn't care for the choice of the Roland Mouret cocktail dress under it...weird and in my opinion inappropriate choice. But thankfully it's covered by this coat and she looks every inch a Queen Consort in waiting.
I agree that it was a good choice to cover the cocktail dress with a coat. For me the bow and the necklace are a bit much and given that she rarely wears necklaces I would have left that off so the bow could shine a bit more. Nit picking I know, and funeral attire at that, but hell it’s just my opinion.
I did like her hair, makeup, hat, and earrings...they all worked really well together and you can tell that she put thought into her attire.
Full disclaimer...I’m not a fan of that necklace in general as I really don’t think it has suited any of the wearers (HMTQ, Diana, or now Kate). I believe that The Queen designed it and her designs generally are the best. But that’s just me.