Meghan, 37, was left in the lurch by her dad Thomas Markle when he pulled out of last year's royal wedding at the last minute, but the Prince of Wales, 70, stepped in to walk her down the aisle.
A royal insider told the British Telegraph that Charles has been teaching his new daughter about the Windsor family history and acting as somewhat of a mentor on constitutional matters to the American-born Duchess.
The heir to the throne is also said to have praised Meghan for her dignified handling of her family's public outbursts.
Reports also claim the Duchess of Sussex has helped Harry mend his relationship with his father, which became strained in the years before they met.
Pregnant Meghan also enjoys a close friendship with Charles' wife Camilla, Duchess of Cornwall who paid special attention to Meghan's mother Doria Ragland during the royal wedding.
Eagled-eye fan watchers have spotted the Duke and Duchess of Cornwall laughing and joking with their daughter-in-law at numerous engagements over the past two years.