A.P.C.: Well, this is a relief. In the States, at least, "talking someone down" not only refers to the airliner situation you described, but also means convincing someone to step down from the window ledge of a tall building to the floor inside, or to step down from a bridge railing to the roadbed, before he jumps off and commits suicide.

(Other situations such as your daughter's request would be referred to as "talking someone through" the situation.)

So stop scaring me like that! *G*