Liza Hempstock, who had been Bod's friend for the last six years, was different...

Liza Hempstock, who had been Bod's friend for the last six years, was different in another way; she was less likely to be there for him when Bod went down to the nettle patch to see her, and on the rare occasions when she was, she would be short-tempered, argumentative and often downright rude.
Bod talked to Mr Owens about this, and after a few moments' reflection, his father said, "It's just women, I reckon. She liked you as a boy, probably isn't sure who you are now you're a young man. I used to play with one little girl down by the duck pond every day until she turned about your age, and then she threw an apple at my head and did not say another word to me until I was seventeen."
Mrs Owens stiffened. "It was a pear I threw," she said, tartly, "and I was talking to you again soon enough, for we danced a measure at your cousin Ned's wedding, and that was but two days after your sixteenth birthday."
Mr Owens said, "Of course you are right, my dear." He winked at Bod, to tell him that it was none of it serious. And then mouthed "Seventeen" to show that, really, it was.