I’ve not made one myself, not any blanket for that matter. But I know people have used Cotton Tots for example. (very soft and easily washable) The Sugar and Cream would work but might be a bit heavy. For a fancier and more expensive blanket people have used cotton classic, particulary to make Log Cabins, like in the Mason Dixon book. I have heard of people using Knit Picks Shine, a cotton blend. And Blue Sky , I think, has organic cotton which would make a nice baby blanket. I don’t think they would be as warm as a wool blanket- but a nice light weight blanket is good to have too. Babies need all different weights and thicknesses for blankets.
I don’t think you’d have to use multiple strands, lots of the cottons or cotton blends ar worsted weight.