Antonia Forest fans

Yes, to borrow again from Ransome, I see Nicola's reasoning as along the lines, 'Better drowned than duffers' and letting Foley succeed is being a duffer. Forest says she's sussed Foley more quickly than Peter, being less under the spell of him as a recognised authority figure, along with his potential crush (I read Peter's attitude to Foley as a crush, even if he doesn't sleep with Foley's kirby grips or whatever the equivalent might be). If the traitor had been Crommie post Nicola's stint in Lower IV, she might have had similar problems re dealing with an admired authority figure.