When Tara finished her short speech, Sean remained silent for a minute. Then he started to smirk. She was obviously lying. Not the part where she was talking about her having plenty of identities. She was lying about the part where she said haven't gotten attached to any place yet.
It was more than obvious that she in fact WAS attached to the Freeport and the Commonwealth. Why else would she have been standing there? Why else would she have chosen this place for her little sister to stay?
However, Sean decided to not comment on his observation, simply nodded, put his hand softly on her shoulder and said:"It'll be alright. If you need help with anything, just drop by."