Hens have been laying 2 months, small eggs?

[Orphy]

I have some new hens that started laying about 2 months ago. I have had hens before and know it takes a few weeks for them to start laying normal size eggs, but I don't remember it taking this long with my last batch.
About how long does it normally take for the eggs to reach full size? Maybe my hens last year were super birds or something, but these are staying about the same size.
The hens in question are RIR,australop, leghorn and EE.
Their eggs are quite significantly smaller than my older leghorn and BO hens.

 

[feathersnuggles]

Often, after their first hard molt (at around 18 months old) you will see improvement in the size of the egg.