Thomas MATHER married Margaret NATT in Plymouth in 1761 (her sister (?), Mary Ann, had married Samuel WHITE, a gentleman from Portsmouth, there three years earlier and they witnessed the 1761 marriage having previously guaranteed their marriage bond) so the NATT family may be from Plymouth.
Thomas Mather was a commander in the RN and drowned in 1766. His will mentions several relatives including his wife and their 'children'. The only child I can find the baptism for is Frances in Stepney in 1765, although this related link suggests that Elizabeth may be another daughter.
https://www.rootschat.com/forum/index.php?topic=776893.0I would expect Margaret to have remarried (or possibly died) but I can't find any evidence for Margaret or Frances after 1767 beyond a possible burial in Bunhill Fields in 1801 aged 68 which I can't link to a Natt baptism.
Richard