Oscar Pistorius trial: Reeva Steenkamp's death 'end of the world'
Reeva Steenkamp's cousin has recounted her happy memories of their childhood together, and her pain at hearing that the South African model had been shot dead by boyfriend Oscar Pistorius.
Kim Martin told Pistorius's sentencing her death was "the end of the world".
She spoke of Reeva's parents' financial problems, and the fact that she had taken up modelling to support them.
The BBC's Andrew Harding says this is the first time the court has heard about Reeva outside her relationship.
Pistorius was found guilty of the culpable homicide of Ms Steenkamp last month, but was cleared of murder.
He faces up to 15 years in jail, although the judge may suspend the sentence or impose a fine.
Ms Martin was the first prosecution witness as they outlined their case for Pistorius to serve a jail term for the killing.
The defence has argued that Pistorius should not be jailed for the killing - a suggestion branded as "shockingly inappropriate" by the prosecutor, Gerrie Nel.
The sentencing hearing has adjourned and is due to resume on Thursday.
Mr Nel said that he would call three or four witnesses.
With her voice breaking, Ms Martin said Reeva was the first baby she had ever held.
"There was a very strong bond from a very young age," she said.
Ms Martin said Reeva was meticulous and hard working at school and that "family was everything to her".
She said Reeva gave her first pay cheque as a model to her parents to pay for her schooling, because of their financial difficulties.
Ms Steenkamp's father, Barry, wept as Ms Martin spoke.
Andrew Harding, BBC News, Pretoria
For what feels like the first time in this long legal process, the Steenkamp family took centre stage in Courtroom D on Wednesday, and we got a powerful sense of the grief, confusion, health, financial worries and behind-the-scenes negotiations that have preoccupied them over the past 18 months.
In brisk, eloquent style, Kim Martin described Reeva Steenkamp's childhood, her family's financial struggles, her education, modelling career, boyfriends, pets, ambitions and desire to have children. Until then, Ms Steenkamp had only ever been mentioned in court in the context of her relationship with Pistorius.
Mrs Martin met her cousin's "famous" new boyfriend only briefly, and found him shy and likeable, but wondered later about a comment - I'm happy "but we need to talk" - that Reeva Steenkamp had made to her.
Mrs Martin then became more emotional - so did Barry Steenkamp, who slumped forwards, sobbing - as she spoke about the devastating impact of the killing on a "very, very close family".
Ms Martin remembered how she heard on her car radio that Pistorius had shot his girlfriend, and "hoped to God" that he was cheating on her cousin and had shot someone else.
She told the court how she went to her mother's house: "The doors opened and my mother was hysterical and that's when I knew it was true.
"That was for me the end of the world. Everything was just a blur from then onwards."
The theme of the Steenkamps' finances was first raised earlier in the day, when the family issued a statement via their lawyer Dup de Bruyn over revelations in court on Tuesday that Pistorius had made them monthly payments.
It had been revealed that the Steenkamps accepted payments of 6,000 rand (£340; $540) from March 2013 to September 2014.
The statement said: "We were contacted soon [after Ms Steenkamp's death] by Mr Pistorius' lawyers with an offer that Mr Pistorius would contribute an amount... towards the parents' rental and living expenses."
The statement said Mr de Bruyn had also approached the Pistorius legal team over a possible civil settlement and was made an offer of $34,000.
"When the parents were made aware of this offer, they considered it carefully but decided, for various reasons, that they did not want any payment from Mr Pistorius," the statement said.
"This is also why we were instructed to advise that no civil claim would be instituted."
Any money received from Mr Pistorius - about $10,000 - would be paid back, it said.
Defence lawyer Barry Roux told the court on Wednesday his client had given the money "unconditionally" and did not want it back.
The Steenkamps' statement said they were surprised the payments had come out in court as it was the athlete who had asked for them to remain secret.
Wednesday's hearing had begun with Mr Nel continuing to cross-examine social worker Annette Vergeer.
The defence witness on Tuesday said that Pistorius should be placed under house arrest rather than sent to prison, because he would be "a lot more vulnerable than the normal man" in jail.
Mr Nel said her opinion of a sentence of house arrest plus community service "cannot be considered".
"If the court sentence is too light, and society loses trust in the court, they will take the law into their own hands," Mr Nel said. "That's what the court has to guard against."
He said a suggestion of correctional duties working with underprivileged children would not take Pistorius out of his "comfort zone".
Ms Vergeer said there had been other cases of culpable homicide where the opinions she had put forward had been implemented.
The Paralympic sprinter denied murdering Ms Steenkamp after a row on Valentine's Day last year, saying he shot her by mistake.
Ms Steenkamp, a 29-year-old model and law graduate, was hit three times by bullets shot through a toilet door by Pistorius at his home in the capital, Pretoria.
Inside Oscar Pistorius's home
Mr Pistorius said he and Ms Steenkamp had dinner at about 19:00 before going to bed at 21:00. He said he woke in the early hours, spoke briefly to his girlfriend and got up to close the sliding door and curtains.
Judge Thokozile Masipa questioned the reliability of several witnesses who said they heard screams and gunshots between about 03:12 and 03:17, saying most had 'got facts wrong'.
Mr Pistorius said he heard the bathroom window sliding open and believed that an intruder, or intruders, had entered the bathroom through a window which was not fitted with burglar bars.
Mr Pistorius said he grabbed his firearm and told Ms Steenkamp, who he thought was still in bed, to call the police.
The judge said it made no sense that Ms Steenkamp did not hear him scream 'Get out' or call the police, as she had her mobile phone with her.
Mr Pistorius could see the bathroom window was open and toilet door closed. He said he did not know whether the intruders were outside on a ladder or in the toilet.
He had his firearm in front of him, he heard a movement inside the toilet and thought whoever was inside was coming out to attack him.
'Before I knew it, I had fired four shots at the door,' he said.
The judge said she did not accept that Mr Pistorius fired the gun by accident or before he knew what was happening. She said he had armed himself with a lethal weapon and clearly wanted to use it. The other question, she said, was why he fired not one, but four shots before he ran back to the room to try to find Ms Steenkamp.
Mr Pistorius said he went back to the bedroom and noticed that Ms Steenkamp was not there.
Mr Pistorius said this was when he realised she could have been in the toilet and rushed back to the bathroom.
Mr Pistorius said he screamed for help and went back to the bathroom where he found the toilet was locked. He returned to the bedroom, pulled on his prosthetic legs and turned on the lights before bashing in the toilet door with a cricket bat.
When the door panel broke, he found the key and unlocked the door and found Ms Steenkamp slumped on the floor with her head on the toilet bowl. He then carried her downstairs, where he was met by neighbours.
3D animation of the apartment