The 1891 birth, and 1892 death for Robert G GARNER to Clara mother look like the one child....record to see at Benevolent Asylum.
Could be a coincidence of names with WW1 GARNER, but Asylum record might be useful to see.
And five days between marriage and death, 1937?...... and wife Muriel cannot name his parents?
Some certificates would be handy here.