My sister is a resident in Germany, have a permanent resident card, she has her own business and want to visit us in the US but she does not have normal passport, instead she has a Travel Document since she have had a refugee status.
I am a US citizen and would like her to visit for a few months here. Not sure of the process on my end or hers'. Can her family visit using that kind of travel document? what is the process, what kind of forms does she need to apply for? And, do I need to proof anything, like citizenship or sending her an invitation letter?