My DD had a growth spur and now the 5-6 cardigans from M&S are really really too small. And b**y M&S doesn't do a 6-7, they jump straight to 7-8. Her dress and t-shirts are a 6-7 strangely.
When she started school in 2011 I bought a 7-8 by accident so had one spare and bought a couple more when I re-stock her uniform last autumn. But in the year inbetween M&S changed the cut and the ones from 2012 are huge on her.
I wasn't happy with Next or Sainsbury so a friend suggested John Lewis. They have her colour but I have no idea how the sizes are compared to M&S. She has a normal JL cardigan in 5-6 and it still fits despite her being in 7-8 apart from school uniform now.
So if any of you uses JL and could give me a hint that would be appreciated. She currently goes to a phase where I have to change the cardigans daily so I am doing a mad wash/iron twice a week.