Here are some twins. You need to go to Yr.2001 and scroll down to baby then just click on the picture.
ttp://www.kreatieve-brievenbus.nl/koop/index-koop-nl.html
here are some baby designs. Perhaps you can make them twins by embroidering a design twice: 1 normal and one in mirror image so it becomes twins.
Free baby hands and feet at Aunty M Designs.
not free but these are cute...
Artistic Threadworks had a freebie called Benny-and-Boo. It's probably for sale now, I don't know how to find it.
1. here is a page with a sample
Go to "downloads" and scroll about 1/4 of the way down.
Sew AZ has a set not free called Baby Signs - it has two sets of booties and says "Our family was just enlarged by 2 feet" or something like that. And I do remember that this site CuteEmbroidery.com had several sets of twin animals - there were free and I bet you could get some votes for one or another of them, if you asked. Why not just create a design with a arrow pointing down - that says "Twins"? And if I remember right - Ricky has a FSL Twin on her site, too.
Someone posted this site the other day. Lots of cute freebies. On page 3 there are 2 babies looks like they are playing patty cake. Not sure what you are looking for but these are cute.