Mark a folder for sync
Select a folder by clicking beside its name, or click the folder name to open the folder. The right hand sidebar should display information about the folder you've selected or opened.
Click Details in the sidebar.
Click the Sync to Desktop slider to mark this folder for sync. By default, this will mark all contained folders for sync as well. You can unmark specific subfolders within a synced folder, if you only want certain content to be synced.
Note: Microsoft Edge does not display these folders, use Google Chrome instead.
Login to Box.com
Click top left 3 line menu
Click on Picture
Select Account Settings
Scroll to bottom.
You may follow the steps here to add a managed user to your account:
To edit a Managed User's settings:
Box User email@example.com
You may still invite her to be part of your account by following the steps here:
Managed User vs. External User
Inviting user to share a file