Sold to me as vintage on eBay, but you know what some sellers are like on there! Made in India, please see photos - thank you so much in advance for any help! If not vintage, what era do you think it’s inspired by? *EDIT Solved, thank you so much for all the help!!*
River Island began in 1988, but I think the Supreme range is a recent thing. I found the same dress is on ebay now, BNWT and the tags look very recent, so I think this is probably only a few years old at the most. https://www.ebay.co.uk/itm/Shabby-Chic-Country-Blue-Patchwork-Cotton-Dress-14-River-Island-Supreme/284054826844?hash=item4222fcaf5c:g:U-0AAOSwlsNfOV7~&LH_ItemCondition=1000 It's really cute though. It's a mix of styles really. Patchwork with denim is very 70s, but the shape isn't 70s. I also remember patchwork checks from the 1990s
This is a modern garment. Madras patchwork garments have popular since the 60-70s and still are manufactured today. I think the babydoll style is popularizing the look from the 90s.