If anything, I think she'd be less able to move on than Ripley. Ripley lost her crew and spent a day fighting for her life, and she had nightmares for months. Newt lost her family, everyone she had ever known, and the only world she had ever called home, and she spent weeks hiding and scrounging for food, and all as a child. I think the old Dark Horse comics have it right - Newt would be in bad shape.