The older woman buckled under the pressure. She (correctly) reasoned that Amy Johnson would have been say in her 30's
during WW2 when she died, so would have been too young to fly in 1912.
Then when the youngsters asked her if she was sure it couldn't be Amy Johnson, she said that she wasn't sure, but that Amy Johnson would have been in her 20's in 1912 (incorrect - she would have been a child by her previous reasoning).
Had she realised (and said this) there is no way the others would have over-ruled her.
To top it all the older woman was herself named after a woman who flew over the English Channel during WW1! The irony of it.