Recent recommendations, based on reputable research, list the range for dietary protein to be from 10-30 grams of protein per kilogram body weight per day.
Here's the site I use for blanket sizes-about half way down page in bold type: http://knitting.about.com/od/knittingskills/a/blanket_sizes.htm. Says standard baby blanket size is 45x60 inches. When I've made baby blankets, I've made them closer to the actual crib size (28x52), because you don't need them to drape over the sides like a regular blanket.
A baby blanket that's about 34-36 long in both directions, and is made of a light-to medium weight hypoallergenic fabric, like cotton or baby-weight fleece, is probably the best choice. It's large enough to swaddle a newborn, and small enough for an older child to sleep with at night.