Hi Angela,
I have spent some time today looking to see if I could find anything for you. I have a personal connection to adoption and for 25 years have been helping others separated through adoption to find each other (non-profit basis).
Do you have a copy of Phyllis' birth certificate that you could scan to me (in .pdf or .jpeg) ?
From the research I've done today, would I be right in thinking you are the daughter of Percy and Pamela?
Without actually having any birth certificates, it looks as though Phyllis was the fourth child of five, the others all being boys. I have found marriages,children and some deaths for most of the boys.
My guess would be that as Phyllis was 3 1/2 when Hannah died that she probably retained her forenames but it's possible that her surname may have been changed if she was adopted.
My thinking is that as the other children were all boys that maybe they were raised by their father and that maybe Phyllis went to a female relative, either from the maternal or paternal side.
No doubt you would know from your father if he was raised by Sydney and presumably also if the boys were kept together. I see that Sydney didn't remarry till 1959, after all the boys were into adulthood.
I have found lots of information and would very much like to "talk" to you. Perhaps you would be good enough to contact me direct on avril.rosswright@virgin.net
Hope to hear from you. Avril