“But the urge to stand up and bring her back to her chair was so strong that I hated myself for it, and for just about the first time I found myself wishing that Millie was ordinary. Images flashed through my mind of how our lives—my life—could have been and it was as I was quickly blinking away the tears of frustration which had filled my eyes that I saw Jack making his way towards Millie.”

This presages the moment that Grace meets Jack. Though she tries to stay upbeat, she is feeling frustrated with her current situation, as she is obligated to take care of her disabled sister for their entire lives. When Jack swoops in to dance with Millie, Grace is at a moment of weakness. 

“He made me feel special, cherished and, best of all, he adored Millie.”

When Grace is first going out with Jack, he puts on a good show. He is very courteous and accommodating. He also doesn’t mind spending time with Millie, who was too much baggage for Grace’s previous boyfriends. This is how he wins Grace over.

“‘What did you think of my parents?’ I asked when we had been walking a while. ‘They were perfect,’ he smiled. I found myself frowning over his choice of words. ‘What do you mean?’

“‘Just that they were everything I hoped they would be.’” 

After meeting Grace’s parents, Jack seems to be strangely approving of them. Grace is surprised because her parents are not the most doting or loving people. She attributes his reaction to the fact that he had once said that his parents were very distant, assuming her parents seemed fantastic by comparison. This is another piece of foreshadowing.