Here she be:
BEST, DORIS GERTRUDE -
GRO Reference: 1897 D Quarter in WINDSOR Volume 02C Page 430
It’s looking like Susannah L Best is her mother.
1861:
https://www.familysearch.org/ark:/61903/1:1:M7HR-9NV1871:
https://www.familysearch.org/ark:/61903/1:1:VFXP-TXM1881:
https://www.familysearch.org/ark:/61903/1:1:Q27Z-3ZRF1891:
https://www.familysearch.org/ark:/61903/1:1:WM9D-KN21901:
https://www.familysearch.org/ark:/61903/1:1:XS3G-NN21911, in West Ham:
https://www.familysearch.org/ark:/61903/1:1:XWFX-7YQMarriages:
Dec 1855 Halstead 4a 559
RAYNER James
PRIOR Maria Hanson
Marriage:
https://www.familysearch.org/ark:/61903/1:1:XK8G-CD4Jun 1875 Easthampstead 2c 699
BEST Eli Robert
RAYNER Maria Hanson
Children:
RAYNER, ALICE PRIOR mmn PRIOR
GRO Reference: 1860 J Quarter in HALSTEAD Volume 04A Page 292
RAYNER, WILLIAM WALACE mmn PRIOR
GRO Reference: 1858 J Quarter in HALSTEAD Volume 04A Page 275
RAYNER, ASA ALLEN mmn PRIOR
GRO Reference: 1863 M Quarter in HALSTEAD Volume 04A Page 336
RAYNER, AGNES MARIA mmn PRIOR
GRO Reference: 1869 J Quarter in HALSTEAD Volume 04A Page 321
RAYNER, EVA CAROLINE mmn PRIOR
GRO Reference: 1871 J Quarter in EASTHAMPSTEAD Volume 02C Page 393
BEST, SARAH KATE mmn RAYNER
GRO Reference: 1873 D Quarter in EASTHAMPSTEAD Volume 02C Page 400 Occasional Copy: A
BEST, SUSANNAH LAURA mmn PRIOR
GRO Reference: 1876 M Quarter in EASTHAMPSTEAD Volume 02C Page 423
BEST, ROBERT EDMAND CHARLES mmn PRIOR
GRO Reference: 1878 J Quarter in WINDSOR Volume 02C Page 434
BEST, ARTHUR PRIOR mmn PRIOR
GRO Reference: 1882 S Quarter in WINDSOR Volume 02C Page 434
Deaths:
RAYNER, JAMES 37
GRO Reference: 1870 D Quarter in EASTHAMPSTEAD UNION Volume 02C Page 284
BEST, ELI ROBERT JOHN 52
GRO Reference: 1897 J Quarter in WINDSOR Volume 02C Page 256
BEST, MARIA HANSOM 79
GRO Reference: 1916 J Quarter in WEST HAM Volume 04A Page 352
BEST, SUSANNAH LAURA 74
GRO Reference: 1950 M Quarter in ESSEX SOUTH-WESTERN Volume 05A Page 312
BEST, DORIS GERTRUDE born 1899
GRO Reference: DOR Q3/1991 in WESTON SUPER MARE (3072) Volume 22 Page 1252
Jamjar