It seems from the Army Record that John could be economical with the truth.
It seems that he states that he married Mary Jane Sidlow, a spinster, in 1900, and that her son Herbert was his, when in fact he married her in 1913, and she was a widow. Working from the date of birth given on the army record this makes him a mere 15 when he married her!
Mary Jane (Ashworth) married her first husband, Frank Sidlow, in 1900, and Herbert was Franks son, not John's.
Jennifer