Her birth record is in the Lynn, MA VRs, as a daughter of Thomas J. Pinkham and Emily.They are listed in the 1850 census in Lynn.Emily was Emily Libbey who died at Lynn in 1873 (Mass. Deaths for 1873, 256:251).Thomas remarried at Lynn in 1874 (Mass. Marriages for 1874, 262:251) and notes his parents as Ballard and Mary Pinkham.
Your line therefore would be:
1. Richard Pinkham m. Gylian 2. John Pinkham m. Martha Otis 3. Richard Pinkham m. Elizabeth Leighton 4. Thomas Pinkham m. Sarah Bunker 5. Abijah Pinkham m. Rachel Huckins 6. Thomas Pinkham m. Sally Ballard 7. Ballard Pinkham m. Mary 8. Thomas J. Pinkham m. Emily Libby 9. Sara Emily Pinkham m. Orrin Webster Cummings
See my article for the first six generations The Pinkhams of Strafford County, New Hampshire, New Hampshire Genealogical Record 23 (2006):27-76 as well as “History of the Town of Durham, New Hampshire (Oyster River Plantation) with Genealogical Notes” by Everett S. Stackpole & Lucien Thompson (2 vols., Rumford Press, Concord, NH, 1913, reprint, Somersworth, NH 1973) for generations 5 to 8.