@oddandelsewhereand others asking about Beyond Nine trousers- I have several pairs and am a big fan. In fact I’m sitting here wearing a pair! I have only bought the Mabel Linen Trousers (I have green check, purple vertical stripe, navy and black) and totally love them! They are comfortable, high quality linen and are very flattering. So many people ask me where they are from.
In terms of sizing, I am around a size 14 ( a 15 really!!) and have both size S and size M and they both fit comfortably.