It certainly sounds like the family history is confusing, and you are brave to try and sort it all out :)

Assuming Shirley died in the UK and under the surname Skyers, the 1972 death is the only listing I see. In case you want to order the certificate from the GRO, here are the details:
Name: Shirley Skyers
Birth Date: 30 Dec 1920
Date of Registration: Oct-Nov-Dec 1972
Age at Death: 52
Registration district: Nottingham
Inferred County: Nottinghamshire
Volume: 3c
Page: 1262