Just kidding about the Germans, and anyway Brazil fought on the side of the Allies in WW2, and the Germans favourite post war retirement area was mostly Argentina. Hadn't heard about any post war German U-boat visiting Brazil, and if it had of done chances are that the Brazilians would have welcomed it by sinking it.
I think that there's a reasonable chance that the lady may be connected to you because of the areas where she was born and lived, and after all Brazil is a huge country and there aren't likely to be a huge number of people in Brazil with that surname, so the location may well be more than just a coincidence.
People could travel from Britain to South America either via America, or direct to South America, and from the late 1800's up to the 1959 there were only around 61 people with that surname who travelled direct to Brazil from Britain. and up to 1952 there were only 42.
Two registrations for the same person ?, or rather 4 registrations for two twins, the handwritten entry is probably the clue.
For births within Britain, registrations in more recent years were listed by the month in which the registration was made, they used to be listed by one of the 4 quarters of the year. parents have 6 weeks in which to register a birth, and so under the quarterly registration system a birth registration could sometimes be made in either of two different quarters.
However, suppose for example that a registration for a child who was born late in the first quarter, and who's birth could therefore be registered in either the first or second quarter wasn't actually registered until the third quarter, what happens.?
Well no matter what the dates or circumstances are, the birth registration has to be registered and recorded in the correct quarter, so in the case of a late registration two registrations will be made, a typewritten one in the third quarter in which the registration was actually made, and a retrospective one in the quarter in which the registration should have been made, but because the registration indexes in the births registration ledger for the earlier quarter have already been typed up by then, the retrospective registration in the first quarter has to be made in the form of a handwritten addition to that ledger page.
There are other reasons why that can happen, such as an unmarried couple who wish to enter the father's surname on the birth certificate, or who later marry and want the father's surname to be added to the birth certificate and I can't recall if they can also have the mother's married surname and the parent's marital status added, or they want to change the child's forename, or they find an error on the original birth certificate/registration and want to have it corrected.
Actually some people can have 5 or more birth registrations but the authorities will know which one is the current one and only one birth certificate in respect of only one of the registrations will be issued for that person.
There is a time limit for such changes and beyond that the parent or parents will have to apply to the UK Registrar General for permission to apply to have such changes made, that is the official who is in charge of the relevant British registration department.
Without seeing the registration index ledger pages and the birth certificates it's impossible to be more specific about the reason for those two sets of registrations.
However, imagine a scenario such as this one.
In recent years the British law was changed in order to require British children to have their own passport, prior to that a British child up to an age which I can't recall, could be added to the passport of one of their parents.
It has never been a legal requirement for a British national who marries or has a child abroad to register those events via the local British diplomatic authorities.
Now imagine this scenario, a British person goes to Brazil and has a child and the child inherits a right to British nationality from the parent, but the parent only registers the birth with the local Brazilian authorities and doesn't also register it with the local British diplomatic authorities.
Ten years later the parent or parents apply for a passport for the child or to have it added to the passport of one of it's parents and they are told that the child isn't legally a British national because it's birth wasn't registered with the British authorities.
So the parents or parent applies for permission to have the birth registered and a typewritten registration is made in the 1950's birth index ledger and a retrospective handwritten entry is made in the 1940's birth index ledger.
Ten years is a big gap, and I suspect that the reason for the two entries for the same children was likely because the original birth wasn't registered with the British authorities, but only the documents or possibly an enquiry to the UK General Register office for England and Wales will be likely to sort that out accurately.
General enquiries
certificate.services@gro.gsi.gov.ukhttps://www.gro.gov.uk/gro/content/certificates/contact_us.asphttp://www.gro.gov.uk/gro/content/