XP: Fly A Lot? Question...

MarcyIam

My sister lives in Australia and comes home 1-2 times a year and does a few work trips throughout the year domestically.  Needless to say, it's a loooong flight to and from Australia.  So I'm looking to get her something as a gift that can be used/helpful during the flights.  Hope to keep under $50 and not to heavy/bulky so will fit in luggage easily and not add weight. 

Any suggestions?  TIA!