I understand what your situation exactly is. My mom traveled from Kathmandu to USA last year. So in that case i wrote a letter describing everything ie. where she is coming and what she you prefer to eat and so on as iPwN mentioned in his/her comment. While getting tickets i specially told the ticket counter to provide her with wheelchair assistant. Then Airlines personnel will pick her up from the tunnel to next terminal or to a particular section where she should be. And also in the paper asked them to call her daughter as soon as she lands in USA port. MY mom was able to talk with me as soon as she landed to USA port through airlines people. Wheel chair assistant will be perfect way to do for safe and comfortable arrival in USA port.