Hunter Biden wiped away tears as his daughter gave evidence in a trial where he is accused of lying about his drug use when buying a gun.
It was the most emotion the US president’s son has shown publicly during his trial in Wilmington, Delaware.
After Naomi Biden hugged him, she appeared to wipe away a tear as she left the courtroom.
Joe Biden’s son is accused of not disclosing his crack cocaine problem when completing forms to purchase the weapon in October 2018.
Ms Biden, 30, said her father seemed “really great” when she saw him in New York in the weeks before he bought the gun.
She said she did not see any evidence of drug use, and that she also visited him in a California rehab centre.
“I hadn’t seen my dad in a long time, and I knew he was in a rehab facility there. He reached out,” she told the court.
She said they met at a coffee shop – along with his “sober coach” – adding she sent him a text saying she was “so proud” of him.
However, prosecutors also asked about messages and calls where she seemed unable to reach him.
“I can’t take this,” she texted several days after he purchased the gun. “I miss you so much and I just want to hang out.”
Prosecutors put forward evidence and prior testimony which they said claimed Mr Biden was arranging to buy crack during this time.
Hunter Biden was allegedly using crack before and after he bought the gun in October 2018 and is accused of lying when he selected ‘no’ to a question about drug use on a screening form.
He has pleaded not guilty to charges of failing to disclose his addiction and illegally possessing the Colt Cobra revolver for 11 days.
His lawyers have said he was not being dishonest as he did not consider himself an addict when he bought the gun.
The 54-year-old’s ex-wife and former girlfriend also testified earlier this week about his crack use, describing unsuccessful efforts to help him get clean.
Graphic images, including Mr Biden half-naked holding a crack pipe, have also been shown – as has a video of the drug being weighed on a scale.
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His sister-in-law Hallie Biden told the court on Thursday she found the gun and threw it away out of concern for Mr Biden and her own children.
Prosecutors ended their case on Friday and the defence took the stage, with the owner of the gun shop and an employee among witnesses.
Lawyer Abbe Lowell raised what he said were inconsistencies on the screening form, and asked the owner why he approved the sale when Mr Biden’s passport did not show his car registration number as required.
First Lady Jill Biden was among family members in court after flying back from D-Day events in France.
She was seen holding her son’s hand as he prepared to leave the court for a lunch break.
President Biden has also pledged support for his son but said he would accept the jury’s verdict and ruled out using his presidential pardon.
“I am the president, but I am also a dad. Jill and I love our son, and we are so proud of the man he is today,” he said in a statement this week.
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The defence is now deciding whether to call Hunter Biden on Monday as the last witness.
It is not the only case he faces. In September, just two months before the US election, he is set to go on trial in California on charges of failing to pay $1.4m (£1.1m) in tax.