Meghan Markle's half-sister tells her to "step up to the plate" in acidic interview.

“Keep provoking me and I’ll keep talking,” was the resounding message from Meghan Markle’s half-sister on Channel Nine’s A Current Affair last night.

It’s no surprise that Samantha Markle of Florida loves Twitter. It’s a platform, she says, that allows her to speak the truth and, if such ‘truths’ are blown out of proportion by the media, well… that’s everyone else’s problem.

The 53-year-old, who’s wheelchair-bound with multiple sclerosis, is referring to the torrent of messages she’s made public since Meghan, a former actress from California, announced her engagement to Prince Harry of Wales in November last year.

“Meghan’s got a family of her own, she’s just too busy for us,” was one of the tweets sent viral in December last year, after Samantha listened to Prince Harry tell the BBC about the couple’s first Christmas together.

It seems every piece of good news from Kensington Palace is met with a bid for privacy from the 36-year-old former Suits actress, and a nugget of nastiness from her half-sister.

Samantha’s appearance on Channel Nine last night was no exception.

She said she has no regrets about airing her family’s dirty laundry for the world to see, accusing Meghan of abandoning their father Thomas, a former lighting director who is now bankrupt and living in Mexico.

“Honestly, what she could spend [financially] in a weekend would greatly help dad, so that should be a priority,” Samantha said. “I think you need to step up to the plate and make sure he is well taken care of.”

Referring to the Ralph & Russo dress Meghan wore for her official engagement shoot, Samantha said: “If you can afford $75,000 for a dress, you can afford $75,000 to help your dad. That’s how I feel, that’s who I am.”

Listen: In case you missed it, Meghan Markle has brought slut strands back. (Post continues below.)

In December, old footage emerged of Meghan talking about her relationship with her dad at age 18. “We aren’t on the best of terms,” she was telling a friend who was filming their conversation as they drove around Los Angeles.

Years later, and the relationship between father and daughter is seemingly mended.

Thomas also spoke to The Sun about his daughter’s engagement. “I think it’s wonderful, I’m very delighted. I think they’re a very good match, I’m very happy for them” he said in January.

It’s Samantha who has the problem.

“I was sad to see [Markle and her first husband Trevor Engelson] divorce. Not to diminish Harry’s social status or royal status, but in a way Trevor was royal too,” Samantha said.

“I really liked him though and admired him so much because he was so lovely to our grandmother when she was in the nursing home.”

A post shared by Kensington Palace (@kensingtonroyal) on Dec 21, 2017 at 6:00am PST

The 53-year-old insists she isn’t bitter about Meghan’s upcoming wedding. “I was always very proud of her. I never felt bitter or jealous,” Samantha told A Current Affair.

Since Meghan’s engagement, Samantha has used the publicity to promote her ‘tell all’ book and to seal television interviews such as the one aired on Nine last night.

No matter the ‘truths’ behind her allegations, one thing is certain: Samantha is profiting financially from these acidic interviews and stories about her estranged sister.

Prince Harry and Meghan Markle are due to be married at Windsor Castle on May 19.

It’s unlikely Samantha will be invited to the wedding.