Authorities showed "very little professional curiosity" about the family situation of a toddler who suddenly died, a report said.
Poppi Worthington, from Cumbria, was likely to have been sexually abused by her father before she died.
The Cumbria Local Safeguarding Children Board said her family had a "complex history", and if that had been noted more support could have been offered.
The board (LSCB) queried Poppi's mother's ability to protect her family.
In January, a judge concluded that "on the balance of probabilities the child was sexually assaulted by her father before the girl's death, in December 2012.
Paul Worthington has not been charged and denies any wrongdoing.
Cumbria Police have been criticised about their investigation into Poppi's death, after it emerged officers failed to preserve vital items for forensic analysis, either at the house in Barrow or at the hospital, and not leaving the scene properly secured.
Analysis: Colin George, BBC online
The process of learning the full circumstances of Poppi Worthington's death has been long and complex.
Today's Serious Case Review covers the events leading up to the 13 month old's death in 2012 and how agencies responded to her needs and those of her family before then.
But it is just one piece of the jigsaw and there are many more to come.
They include a second inquest into Poppi's death, which will be held later this year, after senior coroner David Roberts said there was "substantial public interest". The first inquest in 2014 lasted just seven minutes.
The Independent Police Complaints Commission is reviewing how Cumbria Police conducted its investigation into Poppi's death and will publish its report following the conclusion of the second inquest.
The Crown Prosecution Service (CPS) had originally decided there was insufficient evidence "to provide a realistic prospect of conviction" and as a result no-one has ever been charged in connection with her death.
However, in January the CPS said it was reviewing the case.
Poppi's mother, who cannot be named for legal reasons, and is referred to as MCN in the report, was 27 when she became pregnant with the 13-month-old, a twin, having had four other children previously.
Despite the situation, the LSCB report described Poppi as a "happy, healthy and thriving baby who was being appropriately cared for" in the months before she died.
However, her household and family background was complex, and the "capacity to parent" of MCN could "have been compromised by her own childhood experiences" - she was the daughter of a woman who had been in the care system as a child, and had herself been placed on the Child Protection Register on more than one occasion.
These "were indicators that at the very least, MCN's... ability to protect herself and her children from harm could be compromised", the LSCB said, noting that her "relationship with any male could be a source of potential risk".
"There is no information that any practitioner considered MCN's repeat pregnancies as what may have been a symptom of unresolved loss or considered an offer of more targeted help and support," it added.
It said that in future all professionals and authorities needed to show more "professional curiosity" and share information about family histories which could lead to earlier interventions.
Gill Rigg, chair of Cumbria LSCB, said: "While the review has identified important learning regarding working with families with complex histories, there is nothing to suggest that her death could have been predicted or prevented.
"If there is further learning from how agencies worked together post [Poppi's death], the LSCB will ensure this is acted upon.
"I am however, confident that much has already changed in all of the agencies involved."
Dr Amanda Boardman, lead GP for Safeguarding Children for NHS Cumbria Clinical Commissioning Group, said: "Although [Poppi] and her siblings regularly attended medical appointments and didn't present any obvious concerns, more should have been done to recognise the vulnerability of the family, in view of her mum's history and the size of the family."
The findings of an Independent Police Complaints Commission (IPCC) review into the police investigation will be published after the second inquest into Poppi's death, which is due to be heard in the autumn.