R.B.
My three favorite tips are small cheap wrapped presents (we use tissue paper) of lots of new quiet toys, reusable stickers, finger puppets, the markers that only write on the special paper and not on the airplane, small books, flat velcro or magnet boards that can create stories and scenes, etc. go to Big Lots, Ollies, or a local clearance store and have fun. The unwrapping of the gift makes it exciting and special and the newness helps keep their attention for longer. Next I suggest a portable dvd player with new and favorite dvds with head phones that go over the ears not in the ears, and calms forte for kids, a non addictive homeopathic remedy (like chamomile) to help take the edge of the excitement off so she can relax enough to fall asleep in a strange place. (Then you can watch a movie on that portable dvd player.) A forth tip is to look for a mom looking person or a grandma looking person to sit next to, someone who looks willing to help out a bit and watch the baby when you need to go to the bathroom, or drop something etc. A nice seat-mate can really make the difference on a long flight. My fifth of my three tips is to buy a Sit 'N' Stroll which is a car seat - stroller - airplane seat, if the plane is not full they may let you take it on to the plane, but even if they don't it is a million times easier in the airport on both side of the flight than traveling with a car seat and a stroller and a booster seat. I used my Sit 'n' Stroll all the time and they advertise them in the airplane magazines for smart travel gadgets. LOVED my Sit 'n' Stroll, that's my best tip.
Safe Travels.