Doris Yates was born in 1904. She was the daughter of William Yates and Emma Moss. Doris' birth was registered in Woolwich, Middlesex. 
Doris died in 1918 of Tuberculosis. Her death was registered in Kingston, Frontenac, Ontario.  The mother listed on her death registration was her step-mother. Her biological mother had passed away when the family was still living in England.
↑ Birth Registration: General Register Office YATES, DORIS LOUISA. Mother's maiden name: MOSS GRO Reference: 1904 S Quarter in WOOLWICH Volume 01D Page 1253
↑ "Ontario Deaths, 1869-1937 and Overseas Deaths, 1939-1947," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:J69M-R2W : 9 March 2018), Dora Yates, 26 Dec 1918; citing Kingston, Frontenac, Ontario, yr 1918 cn 17289, Registrar General. Archives of Ontario, Toronto; FHL microfilm 1,862,880.
It may be possible to confirm family relationships with Dolly by comparing test results with other carriers of her ancestors' mitochondrial DNA.
However, there are no known mtDNA test-takers in her direct maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Dolly: