The Downy Quilts for Kids site has some nice, simple patterns for free.
http://www.quiltsforkids.org/patterns/
Many large pattern manufacturers will offer different free patterns each month. You just need to check back regularly.
Two items I make that are very popular with new moms are a simple hand-sewn felt rattle (I have an applique pattern that I sewed together to make a stuffed animal & I taped together 2 iced tea lids with a bit of rice inside and shoved that into the center of the fiberfill) and a changing pad. The changing pads are super popular. I took the measurements from one pattern & added a simple tie made from bias tape I saw on another site (make it roll up instead of the weird folding required with this one's velcro closure. Here is the link:
http://sewtakeahike.typepad.com/sewt...-changing.html
Note: It says to use pre-quilted flannel, but I just made a sandwich -- cotton, cotton batting, flannel. Then I quilted it, bound it & added the tie. It's super easy to make -- can finish the whole thing in an hour or two and that's if you hand-bind it. I've also made bibs, but it seems like those are lower on the priorities list for moms who really don't have the basics. A diaper bag makes another nice gift & you could quilt it or not.
PS -- Kids will love anything that is made just for them & new moms get so overwhelmed so quickly that the colors in a gift quilt are likely to be the farthest thing from their mind. You can always add some fun textures when quilting if you're really concerned about making it more "child friendly". Heather Thomas makes a lot of baby quilts & says that circles/bubbles are very popular because the little guys love touching the puffy textures.
36x54" is what I often find as the "standard" definition of a crib quilt. Of course, none of mine have been exactly that size, but that should give you a rough estimate.