Outfit needed for Queen's Garden Party

[TomYumSoup]

I have been looking at dresses online, in particular at House of Frazer but am a bit overwhelmed with choice. I am 5'1" and a 10 on top and 8 bottom. Am a Blue Spring and best colours are dove greys, blues, purples and turquoise. I already have www.ebay.co.uk/itm/Mint-Velvet-Digital-Print-Flower-Dress-Size-10-/181342629755 but really don't know if it would be suitable and if so what colour hat, shoes and bag and has anyone seen any nice ones. I understand shoes need to be flatish or wedges (am no good with medium to high wedges) for the garden. Any ideas would be very welcome

[turkeyboots]

I see people going to the Garden parties every year and the dress looks fine. Maybe with a jacket (loads of women wear jackets with dresses) and hat or hair thing.