The register entry for Mary's burial in 1824 indicates that she was 91 on death (but this may have been somebody's guess) - corresponding to a year of birth 1732 or 1733. Although there were BAKER families living in Egham around that time there does not appear to be a baptism entry for Mary Baker in the 1730s (the nearest appearing to be 1722 and 1755). Mary Baker is not an uncommon name and there are many possibilities in other parishes but none of them seem to be close to Egham.