Georgia Rowe, 14, died along with Niamh Lafferty, 15, when they plunged from the Erskine Bridge into the River Clyde in October 2009.
Both girls had been residents at the nearby Good Shepherd Centre in Renfrewshire.
Georgia was removed from a foster placement with her aunt in 2008 and taken into care in Hull, East Yorkshire.
She had been fostered by her aunt in Sorn, Ayrshire, as a baby because her mother was unable to care for her.
But the placement broke down when Georgia began to behave erratically and eventually she was taken back to Hull in 2008, before she was returned to Scotland the following year.
Alison Wallace, a social worker at East Ayrshire Council, said she was "surprised" to hear that Georgia had been moved to the Good Shepherd Centre.
She told Paisley Sheriff Court inquiry: "When she was in East Ayrshire she was nowhere near the criteria for secure accommodation."
It had been her understanding that Georgia would be placed with her extended family in Hull. But, in fact, Georgia was put in two foster placements before being transferred into secure accommodation in Hull.
Ms Wallace said East Ayrshire Council social services were given no further information about Georgia after she left her aunt's home.
She said she learned that Georgia had come back to Scotland only on hearing of the double tragedy.
Sheriff Ruth Anderson asked: "Nobody kept you up to date with what was happening to the child in Hull?"
Ms Wallace replied: "No."
The sheriff went on: "Were you surprised that Hull never once contacted you?"
Ms Wallace said: "Yes, obviously.
"The Good Shepherd is a centre we use."