Re: suggest airline for first time international travel........
If you make prior arrangements, at the time of booking, and tell them that the passenger requires assistance during travel and also during the transit phase, a solution can be worked out.
almost every airline offers these services for minors and children traveling alone. I am sure this criteria could be applied to the elderly as well. Just make sure you ask for it while making reservations. Further info can be had from the website of the concerned airline (s)