We have the Alex bag the large one, and Sprocket is larger than your Coco, Sprocket is 10-12lbs, remember you also tend to take a blanket and or a toy. No matter how much room Sprocket has large or small somehow he expands or curls up to fit. Laws of nature kind of thing. Maybe Coco is better than Sprocket in the manner. Also remember your baby will grow some more, Sprocket grew 2lbs and atleast another 1/2" or so legs and 1" body after we got him and he was 2 yrs old when we got him! Like a teenager grows into a man kinda thing, these bags, tho they are expensive are really nice. We just used ours for in flight travel as well as our every day type bag, we've had it 2 yrs and no signs of wear. I like it cause it doesn't look like a "dog" bag, and everybody has a giant purse so no one notices.
. Hope this helps.