No matter what the reason, because of her, her father and sister lost their lives. She has the responsibility, and even the obligation, to give all her love to this child!
She never talked to Robert Thomson about Tommy in the beginning because she hadn't thought of developing their relationship further. So, there was no need to tell him. But when their relationship started to become ambiguous and confusing, she didn't know how to tell him!
It was true that he was the only man in her life. She had liked Dylan King in the past, but that was a long, long time ago. The problem was, Robert was not Tommy's father! How would telling him change anything?
Moreover, how could the Thomson Family accept a child like that? Even her own mother couldn't accept Cynthia Smith's child, let alone Robert?
But if she wanted to take care of Tommy, what should she do with the baby in her belly?
She knew very well, that once she really got together with Robert, she might have to give up Tommy.