I don't think the first item you have listed, " Lightroom 4 Catalog", is a folder. I think it is the master catalog itself, a .lrcat file. LR puts the backups into a folder it creates, titled "Backups". To discover where it is go to Edit/Catalog settings and set Backup to "Every time LR is closed". Now close LR and when a box appears asking if you want to backup the catalog, note the location listed in the box.