While on the subject of Billie Jean, I chanced upon this:
https://books.google.com/books?id=Yw...motown&f=false
R & B Roundup's [[second column first full paragraph) mentions Saundra Edwards & Billie Jean Brown, although the identification of them as the Beljeans on 'Camel Walk' is not correct and the date is off as well.
Perhaps they were the background vocalists for the b-side, 'The Chaperone' .The write-up in TCMS Vol2: 1962 proposes either the Andantes or Billie Jean's group as providing backgrounds.
Could the Beljeans be Saundra & Brenda on Chaperone???