It is this one 
I know it is expensive and I am not the kind of person that would ever normally spend that much money on a skirt (usually no more than £20) but I had a session with a personal shopper last week and she gave it to me to try on and it looked AMAZING.
I am 5ft 8 and it touches the floor (which is unheard of in maxi skirts) and a size 14-16. This skirt makes me look slim and my tummy disappear 
It is truly magical and makes me look much less frumpy than normal - I am totally in love with it! 