That's a great look on her. But £800 for a blouse (according to HRHDuchesskate anyway)! Blimey.
It's a good, fresh look - I think she finds the slightly lower key events easier as she can go 'business', or the full-on dress events as she can go 'princess'. It's the formal daytime events than can be trickier it seems - I guess there's less choice and inspiration available so she can slip into matronly.
That's an expensive blouse though. I just hope it gets reworn! It's the expensive clothes that are never seen again that get me.