You can find this more on this woman and her ancestors by plugging in the names below at: There are more records.
https://familysearch.org/
United States Census, 1870 Barnstable, MA
(https://familysearch.org/pal:/MM9.1.1/MDSX-BW3
William Crocker M 61y MA
Rachel Crocker F 56y MA
Nymphas J Crocker M 26y MA
Daniel W Crocker M 24y MA
Ellen F Crocker F 22y MA
Rachel H Crocker F 19y MA
Alexander Crocker M 12y MA
U S Census, 1850 Barnstable, MA
https://familysearch.org/pal:/MM9.1.1/MD9D-YL4
William Crocker M 41 MA
Rachel H Crocker F 36 MA
Nymphas P Crocker M 6 MA
David W Crocker M 4 MA
Ellen F Crocker F 2 MA
Martha Crosly F 41 MA
Massachusetts, Births, 1841-1915
https://familysearch.org/pal:/MM9.1.1/FXWY-9JM (cannot load image right now to see if this birth indicates Female - but most likely your Ellen by the date.
Crocker
Birth event date: 01 Feb 1848 Barnstable, MA
father: Wm. Crocker
mother: Rachel M. Crocker
https://familysearch.org/pal:/MM9.1.1/N71L-CPV
David W. Crocker
Death 25 Sep 1899 Boston, MA
residence: Somerville, MA
street address: 53 Winslow Ave.
Male age: 53 Married
birthplace: Barnstable est 1846
cemetery: Mt. Auburn Cem.
father: William Crocker birthplace: Barnstable
mother: Rachael Kelly (other record says Kelby)
Massachusetts, Marriages, 1695-1910
https://familysearch.org/pal:/MM9.1.1/FCML-D2G
groom William Crocker
bride Rachael H. Kelley
marriage 24 Dec 1842 Barnstable, Barnstable, MA
Massachusetts, Deaths, 1841-1915
https://familysearch.org/pal:/MM9.1.1/NWWP-VGZ
Rachel H. Kelly Crocker
Death 20 Jan 1890 Barnstable, MA
residence: Barnstable, MA
Female age: 75 Widowed
birth Barnstable, MA est birth 1815
father: David birthplace: Barnstable, MA
mother: Patience birthplace: Barnstable, MA
spouse: Wm. Crocker