Elvira, Mistress of the Dark has offered Meghan, Duchess of Sussex some "beauty advice"

Cassandra quipped on Instagram: "Hey princess, if you ever need beauty advice from a queen just let me know."

The 43-year-old royal - who has Prince Archie, five, and three-year-old Princess Lilibet with husband Prince Harry - spoke with her "dear friend" and hair colourist Kadi Lee recently when she recalled asking for help after trying to dye her own locks.

She said on her own 'Confessions of a Female Founder' podcast: "It was 2020 - it was very much 2020.

"My family had just moved to California. We were staying in our friend's home and because it was the pandemic, I kept ordering boxed hair dye, and I thought I'm gonna look just like she does on the box.

"And instead it was this very inky, almost Elvira-esque black hair. And I texted [hair stylist Serge Normant], and he said, 'You need to see Kadi.'

"And you came over. I mean, we were masked and all the things. It was such an interesting time, but I remember that day so well."

Last year, Cassandra accused Ariana Grande of being rude during an awkward backstage interaction at one of her performances.

During a question and answer session at Knott's Berry Farm in California, she alleged: "She came and she brought 20 guests. So she wanted 21 tickets. We're like, 'OK.'

"We give her the tickets and she comes backstage. She asked if I could take pictures with all of her friends and relatives she brought."

Elvira said she posed for photos and signed autographs for Ariana's group, and then asked for a photo with the '7 Rings' hitmaker.

She added: "I say to her, 'Can we take a photo together?' And she goes, 'No, I don't really do that.' And then she left before my show started. All her relatives stayed, and she took off."

The so-called Queen of Halloween shared screenshots of an article about the encounter on Instagram, and Ariana has now responded and apologised while giving her side of the story.

She commented: "I'm so disheartened to see this.

"I actually don't even remember getting the chance to meet you because i had an anxiety attack and to my memory, left before the rest of my family (this was around 7 years ago and at the time i was really not great with being in public crowds or loud places)... but if i'm misremembering this moment, i sincerely apologize for offending you so. (sic)"