COMPUTER HELP?? IMOVIE AND PHOTOBOOTH?

Hello! My sister was playing on my Macbook Pro and she was trying to clear my desktop so she could see my background (because i had a lot of apps on it) and she put all of it in the "trash" on my dock and then she clicked something on the top left corner and it deleted EVERYTHING that was in the trash..so now i have no iMovie and Photobooth..Any suggestions? Do you know how to get then back? THANK YOU<3