This is heart - shaped tattoo on shoulder. Tattoo has no outlines, but has many ornaments inside. You can see various types of details - floral details, lines, circles, dots. Maybe include kids' names within design somehow.
"Use a white light switch cover and decorate your own with sharpies!" Look, I tried decorating something with horizontal Sharpie patterns and it did NOT look like this. Also, do you really want to buy all those colored Sharpies? give your room color.