Allow a non-admin user to do User Admin or Repo Man

 I have granted this user the role "User_Admin," but she cannot manage users unless I also assign the role "admin" which is global access to all of the admin applets, all security groups, etc. She also needs Repository Manager, as she is Content Manager for an entire business unit. She does not need the other admin applets. How can I grant access to individual admin applets without giving her access to system destruction?
Thanks