Lillebet and Margaret Rose ALWAYS referred to their uncle as "Uncle David", which was his given name. The idea that Princess Margaret, years later in conversation with Prince Philip, would call him "Uncle Edward" is totally preposterous.
At her coronation, Queen Elizabeth II had 2 children (Charles and Anne). That would make her only sister third in line to the throne (not fifth, as claimed by the bogus announcer). Yes, years later 2 further children pushed Margaret back to fifth in line - - but certainly NOT at the time of the coronation.