We have to fly long haul too often and found:
A torch - play with it under the blanket.
Pretend purse - For some reason mine likes old credit cards in it. Also cut up one of those really small 3" X 3" books and put them in the card holder bits. She loved it.
A few tips which have saved out bacon.
If you are travelling with someone else order a special meal. The special one usually comes at least 30 mins before the other so you both get to eat without your hands full.
Don't give her milk etc until you are hurtling down the runway taking off. I've been duped before thinking the taxiing is only a few minutes from take off and then sat on the runway and she's drank the milk and we're still on the ground.
If you are taking calpol as back up, make sure its in the seat pocket in front of you and not in the overhead locker - screaming child and the seat belt sign for turbulence for an hour straight after take off don't mix!
Lie to the air stewardess about her weight/size to get a baskinett. Even if she won't go in it it's a great easy to reach dumping ground for all her paraphenalia!
Good luck with the flight. She may just love it and be in baby heaven - sitting on mums lap as much as she wants with food usually on tap to keep 'em quiet!