Striped Bootees by Melody Griffiths

Striped Bootees

Crochet
Fingering (14 wpi) ?
19 stitches and 24 rows = 4 inches
in double crochet
3.0 mm
3-6 months, 1-2 years, 3-4 years
English

I am sure there is a mistake in the sizing for this pattern but cannot find errata anywhere. My daughter is 19 months and her feet are more than 13cm long which is the size given for age 3 to 4. Go off the measurements of the length, not the ages