A few years ago a friend of mine with her husband became custodial parents of a teenage girl after her adoptive family (another family in their ward) decided they no longer wanted her. Initially, things went well with the original adoptive family. They brought her home from far away. She got along well with others. She met the missionaries. She joined the church. And then it was time to go to the temple to be sealed as an eternal family. It went something like this:
Teenage adoptee: “Well, I don’t really want to be sealed to you.”
Adoptive parents (with shock and horror): “After all we’ve done for you? Why not? We love you!”
Teenage adoptee: “Someday I want to go find my mom. I want to be sealed to her someday.”
And that was the end of their family unit both eternally, and temporally. They kicked her out of the house and that’s how she ended up with my friend.