Once i get my sister and her child here to the UK on an approved visa, would she and her children be able to travel to the United States and possibly live there? how long does she have to stay in the UK to travel to the US. Sorry if this seems like a dumb question. If not allowed to go to the US, what paperwork would be required to travel to the United States from the UK, and how long would that process take? thanks for all your help: )