Qld Birth
1897
#C10118
Edith May Bremming WALKER
Parents: Alexander Frederick WALKER & Emily SMALLWOOD
Qld Marriage
1935
#B20335
John THOMPSON
Edith May Bremming WALKER
Birth records are closed for a 100 year period in Queensland so you will not be able to find a birth record for Frederick George if we assume that he did not live with them until after they were married - that would make him born in the mid/late 1920s.
Edith was aged 38 when she married - are you sure that Frederick wasn't her biological child, born before the marriage?
Edith and John (Jack) lived at 18 Lamington Avenue for a long time - from the mid 1940s till the 1970s. I have followed them through the electoral rolls and they are the only THOMPSONs registered to vote at that address. Prior to that they lived at 43 Chester Street in the Valley.
Debra