trying to figure out what size this would be?
They are adult socks. I looked on Ravelry to make sure and it’s adults modeling them. 
Do you know of a pattern like this for a little girl (age 5) or could I take a basic pattern and use the shell design?
I found these notes on Ravelry
http://www.ravelry.com/projects/wannawanna9999/little-shell-socks
It sounds like she made them for a little girl but some of the others sound like adults, thats why I can’t figure it out.
Here is another one for a child.
http://www.ravelry.com/projects/maramcp/little-shell-socks.
I sent a couple of messages to the above ravelry members maybe someone will get back to me soon, I would really love to have these ready for daughters birthday.
Sure. It’s easy to to do. The pattern stitch is a multiple of 7 stitches so find a childs pattern and you can just use that shell stitch on it. You just have to make sure the stitch number works and it’s only ont he top of the sock so it’s extra easy. Or you can use this pattern, but translate the directions to fit your needs. Have you made socks before? If so then you know the mechanics of it so it should be easy.