1759. Feb. 11 Martha Daugh'r of Josiah & Mary Allen b. last Thursday. [In 1759, 11 Feb is Sunday, 8 Feb is Thurs, and 9 Feb is Friday.]
↑ 3.03.1 Originally Matthew was used for both sexes, but disappeared as Martha became the preferred form for females. So these two recordsS1S2 appear to apply to the same person, differing only in gender. Because the father Josiah had a sister named Martha, it seems more likely that this is the correct interpretation, since Matthew doesn't seem to have any basis in either Josiah or Mary's family.