Melinda, she put the letters on pop dots. You can find them at the craft store in the adhesive section. I usually pick up 3D Dots Foam Adhesive Squares.
The flowers are actually paper flowers. I bought large container jars by Making Memories and one of the jars was fill with those flowers. I got lucky that they pretty much EXACTLY matched Kristin's kit, lol.
To do the letters I cut out each one individually, and then used pop dots/foam dots/adhesive foam dots/etc to make them pop up more from the coaster.
SOooo cute! I seriously wish I had time to make one of these for my daughter's birthday party (TOMORROW) but sadly, no. And we don't have Target's here, so I missed out on the fab coasters.