This is the only SPROAT family I can see in Sheffield on the 1901 census:
RG13/4373; Folio 128; Page 6 - 109 Brunswick St, SheffieldJames Sproat - Head - 30 - Railway Porter - Allerby, Cumberland
Mary Sproat - Wife - 26 - Wigton, Cumberland
Stanley Sproat - Son - 5 - Wigton, Cumberland
John Raisen - Boarder - 26 - Railway Porter - Claines, Worcs
This is a possibility for their marriage:
Marriages Mar 1896   )
BELL   Elizabeth   
EDGAR    Mary         
LANGCAKE    Elizabeth   
SPROAT   James            
WARWICK    Joseph
Wigton 10b 728However, there's a fair gap between 1901 and 1912, so to be sure it's the right family, you really need to invest in Elsie's birth cert.  

Rambler