Here is the marriage index reference for Thomson/Liddell Marriage: Name: THOMSONJOHN Spouse: LIDDELL Florence M Place: PERTH Year: 1911 Ref:693
John Thomson birth as follows: Surname: THOMSON Given Names: John Date: 1881-02-01 Sex: M Father: Hugh THOMSON Mother: Ellison THOMSON Birth Place/Residence: Ridleyton District Code: Hin Symbol: Book: 256 Page: 386 Cross Reference: Note*...no apparent siblings!
As for Florence Liddell, she was not born in WA according to the index, but there are two possible births both of which match the age, but as the marrigae index does not give her middle name either one may be her.
LIDDELL, Florence Maude Birth Father: William Mother: Brown Sarah Event Place: Ball Reg Year: 1883 Reg State: Victoria Ref Number: 14102
LIDDELL, Florence May Birth Father: James Mother: Mary Jane Reg Year: 1879 Reg State: New South Wales Ref Number: 7107