Hi Elizabeth,
I have checked Local Deaths going way back & Rosemary wasn't in them so that is good news.
She was born 1938 & her mother was a Nicod.
Nicod's were Linked to Alphonse Reyrolle.
Alf Nicod was sitting alone at a table & he allowed Mr Reyrolle to share the table in a London restaurant. During their chat Alf suggested Alphonse bring his idea of having an electrical business to Hebburn & the rest is history.
Hope someone can help find Rosemary for you x.