Royals are not really allowed to take a stand on any protests or political movements. Notice that the current Queen never does, and Kate is the future Queen of England. There would have been an uproar if she'd worn black, which is why she just had subtle touches like the sash and clutch. Not lame, in my opinion, just smart enough to know her position and the restrictions that come with it.
Anyway, she looks beautiful and healthy at nearly 8 months pregnant. The emeralds are gorgeous, but I agree not perfect with this gown. I'd love to see her wear them again with something else.