SOPP408: I am not comfortable with thirds in the pedals

This question was sent by Sally, and she writes: I worked on registration for my prelude this weekend and practiced one of the Hymns. I also worked on the Beginning Pedal studies, Day 5, and reviewed Days 1 through 4. These are a struggle for me because I am trying to following the pedal markings and am not comfortable with thirds. I don't usually want to do them with the same foot (either toe/heel or heel/toe) as I am not very accurate. The pedal studies are forcing me to work on that technique. I also tend to not use my left foot on the upper right side of the pedal board, so I am working on this as well.