I will describe a mans size sock, easilly adjusted smaller.

I have used 4 mm/US 6 and knitted it with a gauge of 18 sts and 24 rows to 10 cm/4” square and then lightly felted the socks in the washing machine.

If something is not clear,please send me a message and I will help you.
I do hope you will find this usefull as a guide for knitting your Norwegian socks. Good luck. Best wishes from Grete