Hi can anyone help me in finding 2 missing family members of the springer family from brisbane queensland,

they are John Frederick Spinger born 19 December 1871
and his sister Friedericke Elizabeth Springer born 14 July 1877.
Parents are Gottfried Springer (sprenger) and Friedricke Luise Springer (sprenger) Nee Feldhahn. I do know that John and Friedericke Elizabeth were still a live in 1924 as they are on there mother's death certificate....
Any information on them would great...

thank you