In my opinion, living the military kid life did a lot to prepare her in the area of flexibility - you know, the moving, the packing and unpacking, the living-in-a-friend's-basement-for-6-months-while-your-stuff-is-in-storage kind of life (we lived in this guys' basement for 6 months with our five kids and his wife and five kids - all in one house. Mealtimes were a hoot).
Definitely Teen Missions was the biggest help (summer 2003, age 16) - she lived in a tent, laundry and baths out of a bucket, nothing but rice and beans to eat, coming home with a parasite, snakes dropping on her shoulder out of trees. But those are not the things she took away from that experience. She tells stories of the individual people she met - the doctor who treated them in Cuba knowing he could have gotten in big trouble for it; the lady who had no parting gift for Deb, so she gave the only thing she had - a purple lipstick; the Cuban boy who questioned the government at the youth camp, and was missing the next day; the "missionary" who wouldn't give them their water purifyer (we think she was in cahoots with Castro). She remembers the perfect provision of God - money came in from places we would never have dreamed of; the doctor when they were sick; the dog they were served when they craved meat and there was none. She talks about the complete protection of God when so many things could have gone wrong. She came back from her Cuba trip with a completely different world-view - her world was instantly huge, and there were hurting, lost people out there who needed to be ministered to. Even where there were Christians, they were in hiding, persecuted, fearful of being found out.
We've always been in missions-minded churches so she grew up hearing missionaries talk about God's faithfulness to provide for every need. But it's a different thing entirely to live it out, to see it firsthand, to experience the hunger and sickness and fear of being thrown in jail in a communist country and know that God holds you in His hand.
Her New Zealand/Australia trip was in 2005, and while the circumstances were not nearly as nerve-wracking, it was all part of the plan. She went as a leader on that trip and I would say she probably learned a lot about being a servant - she was the chief cook for 20+ people, three meals a day. They learned a lot about thankfulness - that pumpkin soup was hard to get down and there was a LOT of it. They weren't allowed to throw food away, so it had to be eaten. She definitely ministered to her sister, who wouldn't have gone on a missions trip without moral support, so she helped change Abbie's life too.
I would like to say that I did a great job of preparing her for the mission field, but that would be a lie. God did all the preparing, bringing people and experiences into her life to teach her everything she needed to know about trusting Him fully. He did a great job.
Be thankful ~