Ideas for what to wear to a post Olympic boat party on Thames

[Liveinthepresent]

Dress code says casual but athletes and maybe celebs will be there- it's not for me but a dear friend - she is currently feeling overweight - probably an 18 - in 40s.
Not much budget but maybe even just some different ideas will help get her thinking about adding to what is already in wardrobe to put something together.
What would you wear?

Anyone ? She is panicking ..

Ooh, lucky her! No specific ideas, but I would definitely stick to red, white and blue as my colour palette!

How about the grey union Jack scarf from scarf envy? With white top and dark coloured jeans, I'm thinking plum, and a navy blazer and silver sandals.

Not linen trews Obv.

Thanks so much for replies - chaos you sound very stylish - love the sound of that! Will have to see though as it might be too hard starting from scratch - we started a bit of a maxi dress search but I know these can be a bit high risk - found some interesting gold options!

Ooh, gold would def be a good option, after today! If she's not feeling particularly confident at the moment, she may be more comfortable jazzing up clothes that she already has, rather than wearing something new. Not sure about maxi dress, I think you have to be very slim to carry them off, but happy to be corrected on that! Does she have a good pair of jeans/ trousers she can build an outfit around?

Yes we thought that with the gold! I have a couple of maxis and am a 14 that's what I meant about high risk !
Will investigate trouser options next.
Very jealous - I would love to be going as well.