Easy PHP photo gallery generator

Hi folks,
I am creating a website for a photographer friend who would like to have an area on their site where clients can go and view pictures (a separate area for each customer). My friend would like to be able to add the photos from each session herself rather than rely on me to create a gallery every single time she needs to add a new set of photos. She is not especially technically minded however.
SO … If I can teach her how to create a new folder on her server for each of her clients and upload the photos into that, does anyone know of any php gallery generator code that will automatically pick up any files (and their filenames) in the new folder and create a gallery on the fly? All she would then need to do is copy this PHP code for each new folder she creates … Does that make sense? PHP is not my forte - I’m more client-side than server side :frowning:
THANKS