Hello Wardy1
Your grandmother must have been or is Mary Atkin nee Halke. Her parents were Arthur and Lilian Halke (nee Barnes) they had a son called Clifford who died aged 30 minutes in 1914 and Mary their daughter was born 1920. Arthur her father was the son of Walter Halke -your great great grandfather(born 1849 married Sarah Ann Howe 26 December 1872 at St Philips church) he was his 4th child. Walter Halke was the first child of Henry Halke born 1825 Islington London and Emma Halke nee Senior born 1829. Henry Halke is your great great great grandfather and he is my great great grandfather. I know that Henry's father was called George and he was a gardener married to an Elizabeth? Emma Senior your great great great grandmother was born in Sheffield on Silver Street in 1828. Her father was called John Senior born 1802 and in the 1841 census an Amelia Senior is living with the family aged 68 who most probably was his mother so was born 1773 - Amelia Senior is your great great great great great grandmother!
Hope you find this useful