My SIL asked me to make a simple baby blanket for her. She is due with her 4th in July, and it's a boy! Yay!

I just want to make one of the simple cotton waffle weave blankets with the satin edge. I have the satin already, but I am having a heck of a time finding where to buy the cotton from! All of the fabric I am finding is all heavy-weight or utility fabric. Nothing soft and cuddly.

Think this is something I should go to the store and buy? I just figured I could find more colors online! Anyone make their own baby blanket?