How to create private galleries
Step 1
Step 2

While creating a new gallery, set the Gallery Type option to “Private”
Step 3

Check the users from the list you want to have access. You can select as many users as you want.
Before making a gallery private and accessible to specific users, the users must first have their own user account. You can always create a new user account for them if they have not yet signed up by going to your WordPress admin > Users > Add New.