Can anyone help me please?

I'm trying to complete my friends family tree. His mother Gillian Holland (maiden name eary) was born 28/02/1948. She was born as Gillian BALLARD ad adopted from birth. On her birth certificate her mother is listed as Helen Elaine Ballard. She has given a home address of the Adam and eve pub uxbridge road Hayes. Someone a while ago found her on the electoral role at this pub from 1947 to 1949. That's where we get stuck. How would we be able to trace her either before or after that? We have no further information about her
Thank you
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