My research has found that Charles was not the only child of Albert and Emily. He was one of at least seven children they had, as follows:

Agnes Jane, b. abt. 1893, (baptised on 11 May 1893)
Charles Henry, b. abt. 1893 (baptized on 11 May 1893)
Minnie, b. abt. 1894
Frances Lily, b. abt. 1900
Ethel May, b. abt. 1901
Elizabeth Anne, b. abt. 1903
Arthur Percy, b. abt. 1908

Agnes and Charles were born in The Vale of Glamorgan, but between 1893 and 1894 the family had moved to Tai’r Heol, Nelson.

News:

November 23^rd 1918.

Died of wounds.

Mr and Mrs Albert Sims, 21 Llanfabon Road, Nelson received the sad news on Sunday last that their son, Private Charlie Sims, 94093, Royal Welsh Fusiliers has died in France as the result of wounds received in action between November 4^th and 7^th. Private Sims who was 26 years old was called to the colours last May and was attached to the 1^st Monmouthshire Regiment (59479). Later he was transferred to the Royal Welsh Fusiliers and with them proceeded to France.
He had only been in the firing line about 6 weeks.
Prior to enlisting he worked at Abercyncon, He was born in Cowbridge.

[Source: Merthyr Express]