I just sketched up the dimensions and used a Tweet Tweet by Keiki charm pack plus cream muslin. The back is a nice Valori Wells flannel. I'll show pictures of the final quilt once I figure out how I should quilt it and then put on a binding. I'm thinking something pink for the binding because 1) it's for a baby girl, and 2) the colors aren't too girly on purpose, but the flannel a green agapanthus print making it even less girly. Pink binding could draw out the pinks in the Tweet Tweet and contrast with the green. But I don't have anything suitable in my stash, so it's a little mission for the weekend (darn, I'll have to go to the quilt shop). This baby is coming within the next 2-4 weeks so there's no time to waste!
I used this tutorial from Quilt Taffy for a quilt as you go baby coin quilt with somewhat different dimensions. Overall I'm pretty happy with it so far - though I'm not sure my stacks are as straight as they could be. I started out pinning like crazy (see below), but ended up with fewer and fewer each strip until I just just had a couple at the top and that was it. The tutorial advises more pins due to shifting of the layers. I think this is probably true, but after the first 3 strips the layers were more stabilized.