The 21-year-old woman, known as 'YL', died in January 2020 having suffered from mental health problems which saw her admitted to hospital on a number of occasions, including one stay that ended just before Christmas in 2019.
A safeguarding review into her death has now been completed. It found her death was not predictable but that it was 'incumbent' on the health and care system to learn lessons from it.
'YL was a young person on a journey of transition into her early adult life,' it said, 'YL was also a mum to her two-year-old daughter and a much-loved member of a supportive and close family.
'YL's death was tragic and was not expected at the time it occurred.'
But the report by the Portsmouth Safeguarding Adults Board said housing provision for the homelessness and collaboration between health services needed to be improved.
It said the provision of temporary accommodation 'needs to be more flexible' after YL had requested, shortly before her death, to live in shared housing rather than a hotel room.
The report added: 'The temporary housing market needs to develop to include accommodation in buildings that not only confer access to positive social living and social interaction, but also confer opportunities to develop life skills such as cooking and laundry.
'These facilities are not available in temporary hotel accommodation, making hotels impractical and expensive for homeless individuals as well as potentially overwhelming for young adults inexperienced in caring for themselves.'
It added that care services needed to 'escalate' concerns through the health system when issues worsen.
Board chairman David Goosey said: 'Although the death was not linked to abuse or neglect, there are lessons to be learned, including how services in the city can work together more effectively to support adults with complex mental health conditions and their families.
'Many improvements have already been made and an action plan is being put in place to address other lessons identified.
'We offer our deepest sympathies to the family of YL and others who knew her.'
David Williams, the chief executive of Portsmouth City Council, said the recommendations in the report had been 'noted' and said the council was 'committed' to improving its services.
'We have worked with our partners to develop a multi-agency action plan that focuses on awareness of the impact of homelessness on peoples' mental health,' he said. 'We will work together to implement the plan so that we learn from the findings and make the right changes.'
Superindendent Clare Jenkins, Hampshire Police's Portsmouth district commander, said protecting the public from harm was its 'absolute priority'.
She said: 'Hampshire Constabulary’s mental health lead has taken a thorough look at these recommendations and has reviewed the mental health training delivered to new and existing officers as a result, with new mandatory training implemented.
'We strive to ensure our adult and child safeguarding processes are as effective and joined up as possible and will continue working alongside our partners in implementing any changes identified to improve these processes.'