Kit, as the children would have been baptised in a Christian church, calling someone a heathen then, is the same as calling someone a pagan. It just means that she was not baptised as a Christian, it would not have been meant to be a slur on her character. With most baptism records now, if the person is a different religion to the church where the child is being baptised, it is usually noted. If one of the parents is not baptised, it is usually noted as mother or father not baptised. In genealogy we use baptism records as evidence of birth, but that is not the purpose that they are kept for, it is for religious use.