Can my client reject/approve posts for his/her accounts?
While your clients cannot approve or reject posts, they can edit or delete them from the 'scheduled posts' section.
To enable this access, go to Manage Clients section from the sidebar. Click the 'edit' icon corresponding to your client.
Check the box for 'Can Create Posts'.
Note: If the client has Can View Posts access only, He/She cannot edit/delete the Post.
Now, the client will be able to edit or delete scheduled posts for his/her accounts.