Welcome to the forum, Hewitt.
From 1918 to 1935 John and Ellen Hewitt were at 26 Arthur Street (from electoral rolls).
In 1918 John was an also in the army, no 94813 in B company, West Yorkshire regiment.
Ellen seems to have been Sedgley, not King. Wedding registered 4th quarter 1911 Birmingham, volume 6d page 117. (A copy of the mariage certificate will give you their addresses at the time and both their of their fathers names and occupations.)
Births registered in the surname Hewitt, mothers maiden name Sedgley, since 1911:
George, 4th quarter 1912, Birmingham vol 6d page 275
Ivy, 2nd quarter 1914 Aston, vol 6d page 929
John, 1st quarter 1916 Aston, vol 6d page 722
Joseph J, 4th quarter 1917 Aston vol 6d page 641
Gertrude M, 4th quarter 1919 Aston vol 6d page 855
Elizabeth, 3rd quarter 1921 Aston vol 6d page 892
Albert W, 3rd quarter 1923 Aston vol 6d page 756
Elsie, 1st quarter 1926 Birmingham South vol 6d page 309
Audrey M, 3rd quarter 1927 Birmingham North vol 6d page 572
Violet, 3rd quarter 1929 Birmingham South vol 6d page 14
I found no local births Hewitt - mother's maiden name King.
Here is a copy of John's WW1 army medals card, showing he was first a private in the South Staffordshire Regiment, number 136031.