Try not to overmedicate. Believe me, you don't want a comatose person on a flight. What if there were some kind of issue and your mom needed her wits about her?? The Xanax should do the trick. My dd flew for the first time as an adult (had been about 20 years since her last flight) and she was a wreck. She actually thought she was going to be sick to her stomach due to the fear. But, she remembered all those things I told her and was able to relax enough to get through it. By the third flight of her vacation, she was almost fine!!
So, here are the things I tell nervous fliers, things I still tell myself.....
1. that plane wants to be in the air. it takes a lot to bring a plane down.
2. watch the flight attendents. If they are going about their business, all is well. If it gets bumpy and they have to be seated, watch them....I'm sure they will look almost bored, and be talking among themselves.
3. Heights? Not an issue. Put your mom in an aisle seat. If she can't see out the window on either take-off or landings, she should be fine. You really don't get a feeling of being high once at cruising altitude. Believe me on this one...I have a horrible fear of heights!!!
4. Head over to the fear of flying site. It is incredibly informative. I passed on info there that my dd was able to use...things that the plane will do, sounds you will hear. It sure makes the flight easier for me.
5. Bring something to amuse yourself. Magazines are good, or crossword puzzles..anything that takes your mind off where you are.