Ooooh... this just gave me a great idea! I could use tin ceiling tiles to put over our builder's grade mirror to make a "frame" & then just glue molding to those to give a "finished" look where tiles & mirror meet up!!
A fun project to work on over time with your daughter: Look for different costume jewelry and pins at yard sales and "redecorate" a plain mirror. Every time she looks in the mirror she will remember the time you both spent creating it!