A father who murdered his baby just weeks after adopting her may have slipped under the radar as he was seen as a "positive parent", a review has found.
Elsie Scully-Hicks died in May 2016 when she was 18 months old.
She was subjected to a catalogue of injuries by killer Matthew Scully-Hicks in the eight months he had care of her.
A child practice review said these were never considered anything other than "childhood accidents".
Cardiff and Vale's Regional Safeguarding Children Board agreed that while Elsie's death could not have been predicted it could potentially have been prevented.
Elsie's catastrophic injuries included a fractured skull, bruises and a broken leg at the hands of her adopted father at their Cardiff home.
But a report said professionals failed to "see a pattern emerging with injuries", and that they viewed the adoption as "very successful" with events in the child's life viewed through a "positive lens".
Personal trainer Scully-Hicks, originally of Delabole, Cornwall, had denied murdering the 18-month-old but was found guilty at Cardiff Crown Court after trial last year.
He must serve at least 18 years behind bars before being considered for release.
The review, published by the Regional Safeguarding Children's Board on Thursday, said there were missed opportunities "to raise safeguarding concerns and instigate child protection procedures" and no evidence was seen of injuries being considered as a pattern.
This was despite Elsie needing medical treatment on numerous occasions while in Scully-Hicks's care, including:
- In November 2015 she went to the GP as she could not bear weight on her leg - an X-ray later found she had a fracture
- In December 2015 she suffered a large bruise on her forehead
- In March 2016 she was described as vomiting after falling through stair gates
Despite the list of injures, Scully-Hicks's explanations were accepted by health professionals who lacked "professional curiosity", the report said.
The failure to spot a second fracture on the X-ray in 2015, which was not examined by a specialist paediatric radiologist, meant an opportunity was missed to flag up safeguarding concerns, as getting two fractures from a minor fall would have been highly unusual.
Scully-Hicks and his husband Craig went through a year-long assessment before being formally allowed to adopt Elsie.
The couple decided Scully-Hicks would stay at home while Craig continued to work as a company director with frequent trips away overnight.
But the report said the overall presentation was of a "happy united family" and those working with the child either did not consider or did not raise the possibility that the child was being harmed.
The sharing of information between social workers and the adoption service did not happen until three weeks after she fell down the stairs, it added.
Two social workers and an independent reviewing officer from the Vale of Glamorgan Council saw the large bruise on Elsie's forehead during an adoption review at the Scully-Hicks's home in December 2016.
But they failed to make any note of it and it was not brought to the attention of the adoption court, along with concerns that Elsie was developing a squint.
Analysis from BBC Wales Social Affairs Correspondent India Pollock
This is not the first Child Practice Review, or Serious Case Review, that raises concerns about information sharing.
Different organisations and different people within those organisations didn't share information about Elsie's injuries as well as they should have.
It meant that individually they all had crucial parts of the jigsaw, but nobody had the full picture of the abuse that Elsie suffered, other than her adopted father Matthew Scully-Hicks - the man responsible for her brutal murder.
If professionals had been more curious about her injuries and shared the information properly, safeguarding opportunities might not have been missed and potentially, the outcome could have been different.
During his trial, Scully-Hicks claimed he never harmed Elsie and said she must have suffered her fatal injuries after he changed her for bed at home on 25 May 2016.
She died at Cardiff's University Hospital of Wales four days later, after doctors determined she could not be saved and her ventilator was switched off.
A pathologist said her injuries were "very typical" of a shaken baby.
A CT scan showed she had bleeding on the brain and a post-mortem examination revealed she had also suffered broken ribs, a fractured left femur and a fractured skull.
There was also haemorrhaging within both of Elsie's retinas - associated with inflicted trauma or injury.
Dr Sarah Harrison, who examined Elsie after her death, said her leg injuries looked like those sustained in major trauma incidents such as a car accident.
Who was Elsie Scully-Hicks?
Elsie was named Shayla O'Brien by her birth family when she was born in November 2014.
She was put up for adoption in May 2015, and adopted by personal trainer Scully-Hicks and his husband when she was 10-months-old.
But her birth family said they always hoped she would be reunited with them.
However they were visited by social services in January 2017 and were told Elsie had died in May the previous year.
Following the publication of the report, Cardiff and Vale University Health Board executive nurse director Ruth Walker apologised to Elsie's birth and adoptive family, adding that staff had been "deeply affected" by her death.
Changes have since been made, including that all children referred by their GP for having a suspected fracture will now be seen by a consultant in A&E.
Vale of Glamorgan council's director of social services Lance Carver said it was "difficult to second-guess" what would have happened if the bruise had been recorded properly and he apologised for it not being done.
He said the death of a child was incredibly rare and supervision changes had been made, including more robust sharing of information.
No disciplinary actions had been taken against any members of staff as the report did not "indicate that it would be appropriate".
The National Adoption Service for Wales said adoption services must learn from Elsie's death.