Hi Doug, thanks for the reply.
This Janet was born around the right time and has the right father's name and the right mother's surname but the Janet Tait I'm looking for has a mother named Agnes and was born in Traquair, Peeblesshire. There is an outside chance she was born in Stobo, Peeblesshire but I don't think so. Saint Boswells is 20 miles away from Traquair and 30 from Stobo