She is definitely not going alone and if she does, she won't make it past the check-in gate at Heathrow. The girl never leaves her house, couldn't even spend time in Exeter alone. She is not mentally stable enough to be flying long haul alone, let alone to America. Even Londoners get culture shock in US cities, let alone a delusional woman who's been isolated in the English countryside dependent on Mummy and Daddy for so long that she's in a perpetual state of arrested development.