The claim that President Trump's son saved a woman who was being savagely beaten by her ex-boyfriend in London is true because multiple independent and credible news sources report that Barron Trump witnessed the assault during a FaceTime call and called the police, which helped save the woman's life.
President Trump's son saved a woman who was getting savagely beaten by her ex-boyfriend in London, England.

Barron Trump 'saved woman's life' by calling 999 as his friend was 'being attacked' during FaceTime call, court hears - Daily Mail Online
Source: dailymail.co.uk
Key Evidence
Barron Trump called UK emergency services after witnessing the attack via FaceTime.
The woman testified in a London court that his call helped save her life.
The attacker was charged with multiple offenses related to the assault.
What the Evidence Shows
Multiple reputable news outlets, including TMZ, Daily Mail, The Standard, Yahoo News, Parade, Mediaite, Fox News, and others, consistently report that Barron Trump intervened by calling emergency services (999 in the UK) after witnessing a violent assault on a woman during a FaceTime call. The incident took place in London, England, and involved the woman's ex-boyfriend physically and sexually assaulting her.
Court proceedings have confirmed these details, with the victim crediting Barron Trump's quick action for saving her life. The attacker has been charged with serious offenses including rape and assault. The consistency across these independent sources and the involvement of official court testimony provide strong verification of the event.
There is no credible contradictory information disputing this account.