There's quite a lot about lanyards on the forum so it's always worth carrying out a search. A wiki page on these would be useful I think as they are great for getting all of the information in one location.
Over time, new ranks were introduced and some dropped. During the period the white lanyard was worn by:
From 1939 Hitler Youth lanyards no longer showed the rank of the wearer but rather the appointment and were then known as Dienststellungsschnüre where previously they had been Führerschnüre. For this reason you will see later photographs where the rank insignia seems at odds with the lanyard being worn.
The red/white lanyard with metal catch is for BDM-Mädelschaftsführerinnen and JM-Schaftsführerinnen. Having said that, a 1940 publication shows exactly the same lanyard and describes it as being used by HJ-Kameradschaftsführer and DJ-Jungenschaftsführer. However, this is a printing error because later orders confirm that the HJ/DJ version of this lanyard did not have the metal catch.