This Cardigan is worked in one piece starting from the top and working down, then joining to make the sleeves and edging.
It is made using the lemon peel stitch.

dk / weight 3 yarn I used Paintbox Yarns Simply DK Shade Vanilla Cream 100% acrylic (276 metres per 100g)
4mm hook
5-8x 15-20mm buttons

Sizes
Preemie to 10 years

Written in English US terms with abbreviations for UK terms

Gauge Square
With 4mm hook
Row 1: Ch12, dc in 4th ch from hook and each chain across. (9) Turn
Rows 2-4: ch1, dc in base of ch1, dc 8. (9) Turn
Square should measure 2 inches x 2 inches
If you’re out with a 4mm hook try a 4.5mm hook

The PDF is 33 pages with each size written separately and plenty of photos.