Hannah Daug'r of Ebenezer Kent Jun'r & Sarah Born Dec'r 15th 1740.
The birth record clearly says Hannah. An index entry (here, film 426570 is a transcription of Hingham records by Hosea Sprague), gives a baptism 21 Dec 1740, for a Sarah. This is probably a misreading of the name because in Leicester, where the family moved, a Hannah Kent m. Ezra French (Leicester VRs, p. 174, and no marriage for a Sarah found), and d. 1790 aged 49 (per Briggs, p. 51), matching this birthdate.