I spent some time today, while I working on another computer, searching for you. I did not find any designs that would work. I tried using words like "blended" and "children" in my search. I wonder if one exists. You are right -- they are more common now so one might think they might exist someplace.
There is a set of designs on SewForum called Cute Wedding Party-bride, bridegroom flower girl and More. They are rather child-like but maybe you could combine 2 designs for what you are looking for.
http://www.sewforum.com/viewtopic...
I can't remember having ever seen one. It is more common-place these days.
Depends on how serious an embroidery you need, youcould possibly use paper dolls and dress them up, this could work for a card...