Hi Leisa
There are 2 Bertha Barnsleys born close together. There is the one you have found in 1884 and the one born in 1879 that Barry found.
Bertha Barnsley Sep 1879 9c 509
The Bertha born in 1879 is more likely to be the daughter of Robert and Mary Barnsley as she appears in the 1881 census.
Looking at marriages for Bertha. Again there are two possible dates.
Bertha Barnsley Dec 1906 Ecclesall B 9c 767 to either Ernest Hawley or Sydney Mount
Bertha Barnsley Sep 1907 Ecclesall B 9c 708 to either John Henry Pryor or Ertie Saunders.
The 1907 marriage is on FMP and that Bertha Barnsley has a father named as William Henry Barnsley so not your girl.
I think Bertha Barnsley b.1879 married Sydney Mount in 1906.
In 1911, living at 120 Industry Street Ecclesall
Sydney Mount b.1878
Bertha Mount b.1880
Leonard Mount b.1909