La Redoute can be very good, and sometimes not. I find sizes on the generous side, just got a coat and decent ruffle blouse in 10, French labels say 38, I'd say they fit more like a 10-12.
H&M had a gem of a blouse last year in pale blue or white, lovely cotton and cheap as chips, might be worth checking out what's in stock now. H&M own & Other Stories but that's a shop where I find the prices really unjustified and stuff is often itchy.