Hi,
Don't have anything near that tiny. How's the little one doing? I'd like to hear all about her.
In a pinch, you can take some knee socks you don't want and cut off the foot area. Use the leg part. Whack some holes for the legs and cut out the tummy area enough so she can go potty. You could do this with a tiny child's sweatshirt, too. Just use the sleeve.
Gotta keep that little one warm!