Stella said that during the day, she can imagine flying, but at night when it gets dark, she gets second thoughts.
We talked about travelling this evening, and she recounted some of the things which could go wrong—for example, what if Amy gets upset when the plane is in motion and refuses to be calmed down?
My gut feeling is that things will be all right in the end and that even if some things go wrong, we'll survive it. (That I won't get a meltdown myself from being around a screaming Amy, for example.)
Stella asked whether we really need to decide this now; I said I'd prefer to book the flight as soon as possible due to the volatility of the prices; they might not sell all the seats for an August flight in February, but there's no telling when the cheap seats will be gone.
At the end, Stella said she'd decide whether we'd fly or not by March.
Her preference, FWIW, is still to take the night train. She did say tonight, though, that if Amy and I end up flying, she thinks she should join us so that if something goes wrong she can console Amy. (And it's true that if Amy is upset, she all but ignores me and goes to her Mummy instead.)
So, we shall see.