Moving internationally

Hello friends!

My family of four (hubby and two children, a one-year-old boy and a two-year-old girl) are preparing to move from the United States to Central Asia in July. I am freaking out about the plane ride. We have a 3 hour flight to Houston with an 11 hour layover, then 11 hours flight to Frankfurt (overnight) with an hour and a half layover, then a 6 hour flight to our new city. Any tips for flights with babies/toddlers would be much appreciated! I am super anxious about the travel and want to be as prepared as possible.