Meghan Markle looked "giddy" on her return from vacation.

The 'Suits' actress has recently been on holiday with Prince Harry in Africa, and Meghan apparently appeared to be in good spirits as she and the British royal boarded the Heathrow express train en route to central London.

An eyewitness told E! News: "The pair wore baseball caps and sat in the first class carriage, reading magazines and chatting quietly.

"[Meghan] was smiley and giddy looking."

However, the insider also noted that Meghan was not wearing an engagement ring, as had previously been speculated.

By contrast, former royal chef Darren McGrady recently said Prince Harry could be set to propose to Meghan this December.

The 32-year-old royal has been in a relationship with the actress since last year, and although some insiders thought an engagement would come this month when Meghan celebrated her 36th birthday, Darren has offered an alternative date.

He said: "I really do think they would have been engaged by now. But Princess Diana's 20th anniversary this month in August, they can't trump that.

"And then November is the Queen and Prince Philip's platinum wedding anniversary so they can't trump that either, whereas December they can announce the engagement and they'd be free to marry next year; I think that's what's going to happen."

The former chef - who served Princess Diana and her two sons Harry and William - added that if the flame-haired royal does pop the question in December, it would mean the couple would be able to join the royal family for their traditional Christmas celebrations.