Odd sized school socks anyone?

[karise]

DD needs long grey socks for her new school uniform, but as a size 13 the normal size 12 1/2 to 3 1/2 look absolutely ridiculously large!
We have found some everyday socks in intermediate sizes from H&M & Gap because they are European sizings, but really struggling to find anything similar for school.
Does anyone have any suggestions?

Do you have a tumble dryer? I usually find socks are massive on the first wearing but after being in the dryer they snug up a bit. We get school socks from M&S.

Unfortunately not