National Archives have a digitised WW1 record for a George CHURCH, b Melbourne abt 1887.
NoK given as his mother Mrs Elizabeth CHURCH of Townsville Qld. This name and address is crossed out and an annotation in different handwriting and different ink that his mother is Mrs E Barr, "Rosslyn Villa" 6 Underwood St, Paddington, Sydney; the annotation is dated 24/10/16. His original enlistment was dated 22/2/1915 in Townsville.
He died of wounds 5/8/1916. His kit was returned to his mother Mrs E Church to a townsville address. Unfortunately this notification is not dated.
His undated will gives all to his mother named as Mrs E Barr at the Paddington address. Receipt for his medals signed by E Barr, 1922. Looking again there is a record of correspondenc which states that in 1916 his mother was the person giving information re her change of name.
So it would appear that his mother was possibly using the surname CHURCH and living in Townsville in 1915.
His name is apparently on the Memorial at Villers-Bretonneux in France.
http://www.naa.gov.au/collection/recordsearch/index.aspxJudith