I have a crepe top, obviously inspired by Celia Birtwell, which makes me think it may be early 1970s. Does this woven label (see image) bear out my idea that it is early 1970s and not an early 2000s-Celia-A-Like such as those which flooded the high street after her Topshop collaboration? Although Emma Somerset brand is still going, I did find out that it started in 1969. Other details: French seams, not overlocked. Hand-rolled hem.
Certainly looks 70's to me. Can we see it arms out? is it the same from the front? It's worth keeping in mind this may not be inspired by Celia Birtwell - it could be a concurrent designer to when Celia was producing these style prints.