Martin Asolo-Agogua had not been to sleep after a night of partying when he turned up to his 8am shift on August 3 last year.
He was seen yawning and nodding off before his bus swerved onto the pavement on Watling Street, killing Ada and narrowly missing her five-year-old brother.
The 24-year-old was found to have almost three times the legal level of cannabis in his system after the collision.
Asolo-Agugua was jailed for four years in June after admitting causing her death by dangerous driving and driving while unfit through drugs.
The Solicitor General referred his sentence to the Court of Appeal, arguing at a hearing on Wednesday that it was “unduly lenient” and should be increased.
Three senior judges ruled the sentence should be raised to six years and eight months, and that Asolo-Agugua should be disqualified from driving for five years upon his release.
Ada Bicakci, 9, was killed when she and her five-year-old brother were hit double-decker bus in Bexleyheath (Image: Supplied) Lord Justice Dingemans, sitting with Mr Justice Hilliard and Sir Robin Spencer, said that Asolo-Agugua had “acknowledged that he had destroyed his victim’s family, and his own”, but had “disregarded the risk of danger to others for the period that he was driving”.
He said: “He must have appreciated that he was in no fit state to drive, but continued to drive.”
Peter Ratliff, appearing for the Solicitor General, told the court that Asolo-Agugua worked as a bus driver for Arriva and arrived for work on the morning of August 3, having only returned home from a social event at around 6.30am.
He left a depot in Dartford at around 8.45am in a double-decker bus, with CCTV from the cab showing Asolo-Agugua “yawning repeatedly, appearing drowsy, his eyes appeared to close on occasion, and other road users noted his vehicle was being driven erratically” over around 13 minutes, Mr Ratliff said.
Asolo-Agugua then appeared to fall asleep for “up to 15 seconds”, with the bus drifting across the road and colliding with Ada in Watling Street, Bexleyheath.
After being arrested at the scene, he admitted the two offences in April this year and was jailed at Woolwich Crown Court.
Mr Ratliff continued that Asolo-Agugua’s sentence should be increased as there was “a lack of attention to driving for a substantial period of time” and driving “when deprived of adequate sleep”.
He said: “He must have appreciated from the outset, if he had not already, that he was in no fit state to drive and what he was doing was therefore inherently dangerous.”
The barrister acknowledged that Asolo-Agugua “made efforts to seek assistance for the victim” at the time of the collision and had subsequently “demonstrated clear remorse”.
Asolo-Agugua watched proceedings via a video link from HMP Isis in south London, with his mother in attendance at court.
Gregory Fishwick, representing him, said the case was a “tragedy”, and that while the sentence “might be classified as lenient”, it was “not unduly so”.
He said: “He will never forget this. It was a tragedy, one that he will feel forever.”
On Sunday Ada’s father and mother, Bora and Nevgül Bicakci, revisited the crash site one year on.
Nevgül said: “We will keep fighting for Ada. Please fight with us.
“Because if you are not with us, we are not strong. We need your support. We need your help.
“We want road safety for everybody. We don’t want anyone to suffer like we do.
“Thank you for being here, all of you. It means a lot to us.
“Ada is watching. And she is happy. Thank you.”
Father, Bora, pledged: “No driver will fall asleep on the wheel ever again.”
Ada’s parents have promised to fight for greater road safety following their daughter’s death appealed for the death of their daughter Ada to bring greater safety for pedestrians.
The family has set up a campaign called Ada’s Heartbeart to “amplify the message about road safety [and] shine a light on this important issue”.