Topshop have a petite line I know and I know that their jean sizes are really varied so you can match a lot of waist sizes (think it goes down to a 26" waist) to the leg lengths you want! I always buy from here. Hope this helps a little!
I am an expert on tiny clothes and jeans and where you cannot find them! let me know your waist and bust size and I will help. what leg size do you take? You say size 6 (Next's size 6 is a 28 inch waist, French Connection's size 6 is about 29 inch waist!) and Top Shop has now increased their size 6 to a 26 inch waist. Gap's size 0-2 is a 27 inch waist ..............