Georgia Rowe's aunt, Tanya Oliver, told the inquiry at Paisley Sheriff Court she felt "ecstatic" after visiting her that day and felt the teenager had turned a corner.
Georgia, 14, and Neve Lafferty, 15, died after falling more than 100ft from the Erskine Bridge in October 2009.
The girls were residents at the nearby Good Shepherd Centre, which cares for young girls referred to it by local authority educational and psychological services, social work departments and children's hearings.
Ms Oliver cared for Georgia from the age of nine months as her sister was not capable of looking after her. When the girl's behaviour became too challenging she was taken into care in summer 2008.
She said after visiting Georgia at the centre in Bishopton, Renfrewshire, on October 4 2009, she had high hopes the girl could soon come home.
Ms Oliver said: "The day she died she was all laughter and chatting. She had so much to look forward to.
"We were planning on going ski-ing in February and she tried jackets on in the equestrian shop and asked if they would be suitable for ski-ing."
She added: "I was ecstatic at the end of the day. I drove away from there happy."
The inquiry heard that Georgia had been fully moved from the secure unit into the open unit the weekend before she died after a transition period of around five weeks.
Ms Oliver said she felt Georgia was not ready for the move. The inquiry heard the teenager had a "Jekyll and Hyde" personality, and could veer from being "really lovely to extremely aggressive".
Ms Oliver wiped away tears as she remembered malevolent words Georgia uttered as she left her home in Sorn, Ayrshire, in June 2008 to be taken to a foster carer and then into care in Hull before returning to Scotland.
The inquiry heard Georgia told her: "I can't wait to see you dead. I want to see the blood trickling out of your eyes and your ears."
Ms Oliver said: "She had been venomous to me in the weeks leading up to it but nothing as bad as that." Georgia was sometimes violent, once banging Ms Oliver's head on the kitchen unit and hitting people with "bibles and books, anything".
Ms Oliver said she suspected something was wrong with Georgia and had heard about foetal alcohol syndrome, though Georgia was never tested for this.
The inquiry continues.