Meghan Markle Used Royal Instagram to Subtly Make Political Statements

Meghan Markle's an expert at pushing the envelope when it comes to what's politically acceptable to the Palace, and she proved it with some covert statements on her Royal IG with Prince Harry.

During her time as a Senior Royal, the Duchess of Sussex used the only social media she's allowed to have to make her political opinions known, but she did it subtly, knowing she was wading into dangerous waters with the Crown ... sources close to Meghan tell TMZ.

If you don't know ... Queen Elizabeth and her family are supposed to refrain from expressing political opinions publicly, but we're told Meghan never gave up her previously strongly held political beliefs.

Our Meghan sources say she carefully crafted IG posts to avoid overtly saying what she was thinking or supporting, but the writing was on the wall ... or in the photos.

For example, when her friend and women's rights activist, Loujain al-Hathloul, was imprisoned in Saudi Arabia ... Markle knew she couldn't come out and condemn a foreign government.

Instead, Meghan showed subtle solidarity by sharing a photo of herself with Loujain as part of a bigger post about One Young World ... a UK-based charity which is described as a global forum for young leaders. Meghan's support for the charity began in 2014, before she married Harry. Loujain was imprisoned on the weekend of Meghan's wedding and it's clear that, despite the diplomatic nature of her royal role, Meghan was calling for her friend to be freed by the Saudi regime.

That same post included a photo of Markle sitting next to Canadian Prime Minister Justin Trudeau, shortly after he won re-election -- a low-key shout-out of support for her friend.

Our sources say, for the most part, she knew how to walk up to the line without crossing it, which helped her dodge any issues with royal higher-ups. Call it effective self-censorship.

As we reported ... Meghan and Harry no longer formally rep the Queen in the wake of Megxit, nor will they be referred to as His or Her Royal Highness.

Harry broke his silence over the weekend, revealing it was a tough call to part ways with the family, but added ... "there really was no other option."

Meghan making future political statements on the Sussex Royal IG account is up in the air. The Palace hasn't announced whether she and Harry will be allowed to continue using it, now that they've ditched their Senior Royal duties.

TMZ is further investigating what went down leading up to Harry and Meghan's departure from the Royal Family. Watch our special, "Harry and Meghan: The Royals in Crisis" on Fox network January 29 at 8 PM.