Year – I think it’s hard to say, being that a child might have worn this in any decade of the first half of the 20th century. However, 3d was the average price in the 1940s. However the colour printing makes me think this is a post war pattern.
Size – for an 18 inch head perhaps, or maybe its 18 inches at the widest point. Pattern is a bit vague.
Yarn Size – 3 ply