I don't personally relate to her character much...but after reading the screenplay, I understand more about how she felt about her surroundings and her life. It's obvious she felt trapped by her mother forcing her marry Cal, but she also felt trapped in the first class- you can see it on her face when she is having tea with her mother, and sees the mother teaching her young daughter how to place her napkin in her lap, etc. Even her corset was trapping her...I think with Jack she could really express her feelings and thoughts and know he would not just pat her on the head and laugh. Instead he actually listened to her, something her mother and Cal only pretended to do.