You can set a password to your gallery in the moment you create it or later. It's a great solution for all of you who wants to keep some photos available only for family, clients or yourself.
Check this tutorial that guides you step by step through the process of adding gallery.
If you’d like to set a password to gallery that is already uploaded, log in to your User Panel and go to 'Gallery'.
Choose the gallery that you want to make private and click on the image of a pencil to edit it.
You're now in editing panel, in 'Information' section. Scroll down and you'll see 'Password protect' switch. Change it from 'off' to 'on', and set the password. Save changes.
Now you can share link to your gallery with a password. Be sure that the access will be only permitted to the selected people.