T.H.
Hi M.,
I found flying with my toddler was actually easier than when he was an infant. The airport is the most exciting part (watching planes take off and land - he could have done it for hours!!). The plane might offer an in flight movie which will help otherwise bring things she can't usually have. We found coloring with one of mom's pens vs crayons makes for a much longer art session. Connecting straws and blowing a piece of paper off the tray was also a ton of fun - go figure.
If you expect you may fly home often check out the CARES restraint (http://www.kidsflysafe.com/). And you can walk up and down the isles a bit but only if the weather is cooperative. :)
Hope this helps!
T.
p.s.
Don't worry about other people if she gets upset, they will survive and if you can stay cool she'll calm back down easier and more quickly. Oh and snacks are a good idea too and yes, you can bring your own. I like dried fruit because it takes some work to eat (ie it takes time).