Flowery Angela Kelly Ensamble

This double-breasted lavender coat, floral silk dress and straw hat with dark purple bow and flower trim to one side, all by Angela Kelly was first worn on 20 June 2013, Ladies' Day at Royal Ascot, a particularly happy day for the Queen as her horse, Estimate, won the Gold Cup, a first for a reigning monarch. The Kent Amethyst brooch nicely complemented the lavender hue of the coat:

 

With her jockey Ryan Moore:

This lovely ensamble was repeated about a year later, on 21 May 2014, for a Buckingham Palace garden party, this time accessorised with the Carrington Sapphire Feather brooch:

It's impossible to be sure, due to the low resolution of the images available, but I'm convinced this silk dress the Queen wore on 23 July 2014 to receive the Governor General of Grenada, Dame Cecile La Grenade, at Buckingham Palace is the one from this look - the colour and pattern seem to match, although higher resolution pics are definitely called for!