I made this cardigan for 0-6 month old but after following my tutorial you can make it in bigger sizes as well.
video tutorial and written pattern is available.
this cardigan is worked in parts and then sew them together.i have used dark grey color in dk weight yarn with 3 mm crochet hook.you have to make back, left and right front and 2 sleeves .
design is very simple, I used double crochet.