Frosting Help, Please...?

I am 60 and when I was a young girl my mom made this white, fluffy frosting that would develop a thin, hard skin or shell when it dried. My sister thought it might be called 7 Minute Frosting. I googled a recipe and I just made that and, not only is the flavor wrong, but it has yet to get the shell on it. I remember it getting the skin on it relatively quickly, not needing much 'drying time'.

The recipe I used called for egg whites, vanilla, cream of tartar, sugar, and water and wasn't as thick as I would have liked it. Does anyone know of this frosting. My sister's birthday is coming up and I'd like to surprise her if I can get it right.

Thanks!