It is highly unlikely that you will find a birth record - a baptism record is possible and on occasions the cleric may have entered a birth date if the parents gave it. Bear in mind that the age at death is also what the person recording the death was told - it would not be a certainty. Ann would have been 30 at time of marriage if the supposed birth year is correct. There are 4 baptisms 1750-1755 for an Ann ANDREWS with a further 3 for an Ann ANDREW shown on FMP Indices. This doesn't take in to account parishes which have not yet been indexed.