Meghan Markle addressed students at the University of the South Pacific’s campus in Suva, Fiji during her official royal tour.
The pregnant Duchess told the audience she paid her own university fees using financial aid, scholarships and a part-time job.
In since-deleted tweets, Meghan's estranged half-sister Samantha Markle claims it was all 'lies'.
'Dad paid for her college tuition! She forgot the most important part of her speech and there are receipts for prove it,' Samantha wrote.
'I love my sister but this is ridiculous. You can't lie like this, Meg! Delusionally [sic] absurd!'
Meghan told the crowds about her own experiences at university and the feeling of 'pride and excitement' she felt.
'It was through scholarships, financial aid programs and work-study where my earnings from a job on campus went directly towards my tuition — that I was able to attend university. And, without question, it was worth every effort,' she said.
Meghan's half-sibling then wrote another angry tweet, even tagging the official Kensington Palace Twitter page in her claims.
'Our father paid for all of her education! This speech is not true. She needs to stop hiding the truth,' Samantha added.
After wrapping up their Fiji visit, Harry and Meghan will fly to Tonga and New Zealand before returning to Sydney.