These are nice curtains I think would go (John Lewis) and cheaper! http://www.johnlewis.com/john-lewis-oakley-trees-eyelet-lined-curtains/p341137
Have you seen this aswell? Would go very nicely against duck egg... It's showing out of stock but I know it's a new line so it will probably come back in (it's £25) and really lovely! http://www.marksandspencer.com/Marks-and-Spencer-Crackle-Hurricane/dp/B004689RHY
I would actually avoid dark brown with the duck egg shade even though it goes. I personally prefer lighter and brighter with duck egg. Lovely white furniture would be nice... Oh, also in summer you could have lace curtains (vintage style) like this, especially nice if the room has a long window/ door with windows... http://www.notonthehighstreet.com/marylynlarkin/product/vintage-style-nottingham-lace-curtain A nice venetian mirror would be good: This is nice and unusual from Laura Ashley (on sale) http://www.lauraashley.com/invt/3469186 or http://www.homesdirect365.co.uk/french-furniture-487/mirrored-furniture-7/mirrored-furniture-1772/venetian-mirror-etched-205.htm on a nice dressing table Just ideas... Hope it all works out nicely
How about some thick white fabric (think Portuguese style bedspreads) and bind it round the edges with some wide grosgrain ribbon in a colour close to the colour of your walls or pink? You could probably buy ready-made curtains and then just get a seamstress (or you) to machine around the ribbon.