hi daryl, you will either need to get her death certificate or rely on someone else's death or burial data. Her death cert details are below so you can order it from the GRO...
Name: CARROTT, Mary A
Registration district: Cleethorpes
County: Lincolnshire
Year of registration: 1939
Quarter of registration: Jan-Feb-Mar
Age at death:75
Volume no: 7A
Page no: 851
You may be interested in this website that seems to have several relations listed...
How certain are you of the birth details? It seems odd that you show the precise date but not parents, if you had the birth certificate you would have both pieces of data. Also you say in the bio that she was a twin to Martha but I can't see any records confirming this.
BTW There are several plausible birth records in Lincs and here are just two of the most likely...
Name: WILLOWS, Mary Ann
Registration district: Sleaford
County: Lincolnshire
Year of registration: 1862
Quarter of registration: Apr-May-Jun
Volume no: 7A
Page no: 396
Name: WILLOWS, Mary Ann
Registration district: Louth
County: Lincolnshire
ear of registration: 1863
Quarter of registration: Jan-Feb-Mar
Volume no: 7A
Page no: 582
The 1911 census indicates that Mary had 12 children who were still alive as at 1911 before she died...
CARROTT, Charles Head Married M 52 1859 Gardener General Lincoln Mithern
CARROTT, Mary Ann Wife Married28 years F 49 1862 Yarboro Lincs
RG number: RG14 Piece: 19999 Reference: RG14PN19999 RG78PN1197B RD422 SD1 ED48 SN117
Registration District: Grimsby Sub District: Great Grimsby Enumeration District: 48
Parish: Healing Address: Station Road Healing County: Lincolnshire