Vest or hat?

Started "dd#2's vest", but I'm thinking about keeping it for myself and turning it into a hat. First, I'm not sure I have enough yarn for a vest. Second, the yarn doesn't seem that appropriate for a 10 month old, but very nice for mama. We'll see. I have some organic yarn from Full Belly Farm that I can use for the vest. This way, I use up more yarn from the stash.