Increasing a pattern size
I have a pattern for a baby sweater that's 6 month size. I'd like to make it in a 12 month size. I'm wondering how to increase it. I'd call myself a long-time beginner (mostly baby blankets). This is my first baby sweater.
I knit slightly tighter than the gauge. The yarn I'm using doesn't specify a weight, but it says 50 grams. It's similar to yarns I've used on other baby projects, so it's fairly lightweight, but I know there are thinner yarns.
The pattern says to use sport weight yarn (100 grams, 355 ounces) and size 5 and 6 needles (for different sections). Any help is appreciated (even if it's to find a new pattern!). But I've already made the blanket, and ideally, I'd like to make the matching sweater. Thank you so much!