Identifying an Australian soldier by his uniform

[kdsoph]

The digitised AIF files are freely available to search for, through, download etc. 
http://soda.naa.gov.au/record/3009867/1  Service Records for Baker, 1566.  Digitised.
Plus there's  http://soda.naa.gov.au/record/4292270/1   Pay File  for Baker, 1566.  Not Digitised, but on open access, so likely they would be available for digitisation on payment of applicable fees.

Re the two official transcriptions of the 1915 Birth Certificates, uploaded to reply # 23.   These definitely confirm the girls were born 15 December 1915, they indicate which lass was the elder, and on the younger one's birth registration you will notice that the record shows she has an older, living sibling...   I do not actually understand why the Opening Post (raised less than ten hours earlier  than reply #23) notes they were born ... between June and December 1915. ...   

.......
His identity is a bit of a family mystery and I would be thrilled if it could be solved. I had already posted a request on the beginners' board a few years ago and they were amazing with their information and guidance which included a link to this board.

Re: Gweneth Lydia Fordham birth https://www.rootschat.com/forum/index.php?topic=722500.9

 This is what I have come up with so far...

There are 2 little girls sitting on the soldier's knee and they are my grandmother, Gweneth Fordham and her identical twin sister, Sylvia.

Suspect No. 1 Father Arthur George Fordham (1893-1959)
The twins were born in Waratah Newcastle NSW Australia between June and Dec 1915 to Arthur George Fordham and Lena Agnes Fordham nee Baker (1892-1970). ......

Not to worry though,  I am sure our OP is now sure of the identity of her Soldier, and it is now just a matter of figuring out which lass in the photo is Gwen.        ... 

JM

I am so sorry. I should have qualified my question about the twins' exact age. When I posted years ago (on link #1)  I was asking 2 questions. How do I find out their birthday (the date had not yet been released) and how do I find out who the soldier is. 
The answer came back that they were born 10th or 11th Oct, which would mean Lena was pregnant when she married (and Gwen had been celebrating her birthday 6 months after she was born).  - HUGE SCANDAL! Lena was a Temperance gal and VERY straight-laced.
Then a couple of days ago as we were "comparing dimples", I received the transcripts of their birth certs which states they were born 19th Dec. so at the beginning of the thread I was still not sure and at the end of the thread with transcripts in hand ...I am still not sure but willing to accept the transcript dates of 19th Dec.
Thank you again so much. I am sure the soldier is Lieutenant John James Baker now and as to your question about which is Gwen...I already know...Gwen is the pretty one 

[ecksdochter]

    Found on trove.nla.gov.au
"Newcastle Morning Herald and Miner's Advocate" Sat. 25th Dec. 1915.
     
Family Notices - Births.
     FORDHAM. - December 19, at their residence, "Lenora," Myola St., Mayfield, to Mr. and Mrs. A.G. Fordham - twin daughters - Sylvia and Gweneth.

     Regards,     Dod.
     
     P.S. Also on trove.
"The Telegraph" (Brisbane, Qld.) Fri. 17 Sep. 1915.
     Roll Of Honour. (Listed in the 2nd last column.)
     "Gnr. A.G. Fordham, 2nd F.A. Bde., W." (W on the end = Wounded.)

     Could this A.G. Fordham be the twins father, and the man in the photograph with them?
     A lovely photograph of beautiful twin girls.

     
     
     

[majm]

I think Gnr. A.G. Fordham in the Brisbane newspaper found by ecksdochter here https://trove.nla.gov.au/newspaper/article/179684502 and
https://trove.nla.gov.au/newspaper/article/179684113
is also mentioned here:
The Kalgoorlie Miner of Friday 17th Sept 1915 has under their Wounded List ... 2nd Field Artillery Brigade - Gunner A.G. FORDHAM (Mt Barker).   (it mentions it is the 78th casualty list)
https://trove.nla.gov.au/newspaper/article/87389199
and therefore  would likely be
http://soda.naa.gov.au/record/4024237/1 Albert George FORDHAM, #1581
page 11 of 36,  changes his nok  to wife, Doris Ella Fordham, ... London...
pages 18, 19, 20 AIF extract of marriage, 27 Sept 1916, in England.
so not the father of the girls in the photo...

JM