D’you – d’you want to go to the ball with me?” said Harry. Why did he have to go red now? Why?
“Oh!” said Cho, and she went red too. “Oh Harry, I’m really sorry,” and she truly looked it. “I’ve already said I’ll go with someone else.” (Harry Potter 4 [US Version]: p.397)[Bold font is mine]
I understand that ‘she truly looked it’ means ‘she truly looked sorry’. But if I were to write this kind of sentence, I’d probably write ‘she truly looked so,’ as I’m familiar with ‘I think so.’
Is there any difference if you write ‘she truly looked so’ instead of ‘she truly looked it’?