D.G.
We took my daughter to CA (4 hr. flight) when she was 13 mos. old and the best investment I made was a portable DVD player which you should fully charge before boarding. One with both an AC/DC adapter is perfect. I also took lots of snacks & juice. As far as toys go, anything that is NOT noisy. Definitely request bulk head seats when you check in. I also found feeding her BEFORE boarding to be helpful so I didn't have to juggle food on the plane & changing her right before boarding. (Those bathrooms are TOO tiny for changing diapers in.) The Ergo carrier is also a great idea, my arms & legs got really tired from having her on my lap the whole flight. Enjoy your flight & don't stress over it, I'm sure they'll do good! :)