I did it! I found Jack and Sandra's address! I'm thinking you don't really care, but I'm going to tell you how I found it anyway.
Once upon a time I had a friend named Brent Olsen. Brent and I were in the same ward and worked together in our callings. One day he said to me, "My dad and your mom were best friends growing up." It only took about 2 seconds for me to figure out who his dad was. I grew up hearing about Steven Olsen and considering that Brent and I didn't grow up anywhere near each other, it's amazing we ended up in the same ward.
Fast forward a year. I was anxiously awaiting my mission call. Every time I saw Brent he said "You are going to go to the New York New York South mission (where Brent served). I ignored him because I was SURE I was going to Latin America. When I finally did open my mission call I read "You have been called to serve in the New York New York South mission." Brent was giddy for days.
Brent had only one hope for me: "I really hope you serve in Jamaica, Queens. I would love it if you could meet one of the couples I taught and baptized. They're amazing and they will take care of you."
Can you see where this is going? Yep, Brent taught Jack and Sandra. He taught other random people I met too, people who never joined the church but who I happened to meet while tracting. It seemed I followed in his footsteps throughout my entire mission.
Anyway...Brent and I haven't talked in years but he just found me on Facebook. And what do you know, he had Jack and Sandra's address.
And they all lived happily ever after.