Decorative Mirror Screws How Can I Hang A Small Picture/mirror Onto A Big Wall Mirror?

How can I hang a small picture/mirror onto a big wall mirror? - decorative mirror screws

I have a large wall mirror glued to the drywall above my bathroom sink. In an attempt to break the size of the mirror, I hung two small decorative mirrors directly into the mirror and concentrate on each sink. How can I do nails or screws directly into the large mirror so that you can not crack? Or is there some sort of sealant or adhesive that will keep the big mirror placed in small mirrors can?