No gauge is provided in this pattern and the pattern does not state the finished size of the garments. From the needle size and the picture, it appears a fairly tight gauge for worsted weight yarn--maybe 5.5 or 6 stitches/inch. At that gauge and with the number of stitches called for in the pattern, this would likely fit perhaps a 3-6 month old.

The yarn quantity given for the entire set (cardigan, hat, mittens) is 8 oz.