Meghan Markle and Queen Elizabeth II
Meghan Markle has to adjust her bedtime when she's with Queen Elizabeth II. Pictured: Queen Elizabeth II and Markle watch the RAF flypast on the balcony of Buckingham Palace, as members of the Royal Family attend events to mark the centenary of the RAF on July 10, 2018 in London. Getty Images/Chris Jackson

Meghan Markle will have to adjust her bedtime when she's with Queen Elizabeth II.

According to Sir William Heseltine, the Queen's private secretaries revealed that no one is allowed to go to be before Her Majesty. So, if the Duchess of Sussex will spend a night with the Queen she has to stay up late until the monarch decides that it's time to sleep.

"There'd be an hour or so in the sitting room of everyone sitting around making conversation, and nobody felt it right to go to bed before the Queen did," Sir William said (via Daily Express).

However, one royal broke this. According to him, Prince William and Prince Harry's mom couldn't keep up with the long evenings and found it to be an "agony." Princess Diana had broken this rule a number of times.

"And Diana was driven to such extremes that she'd excuse herself and go to bed, which was thought to be rather bad form, going to bed before the Queen," he continued.

The Duchess of Sussex has to stick with the royals' protocol and practices. In fact, there are certain rules that she needs to follow when she gets pregnant.

When Markle gets pregnant, she has to wait for the day of her delivery to know the baby's gender. Prince William and Kate Middleton are parents to three royal kids, 5-year-old Prince George, 3-year-old Princess Charlotte and 3-month-old Prince Louis. During the Duchess of Cambridge's three pregnancies, they only discovered the sex of their baby on the day they were born.

Also, when Markle delivers her baby, the first person she has to inform is the Queen. She can't call her mom, Doria Ragland, about the news, not until Prince Harry informs the Queen. Also, no matter how Markle loves to travel, she won't be allowed to do so when she's expecting.

Markle won't be able to have baby showers too. This American tradition is very popular today, but the royals don't think that it is necessary especially that royal babies are not allowed to receive gifts.

"A lavish baby shower would be seen as highly inappropriate... there's nothing they can't go out and buy themselves," Victoria Arbiter said while pointing out that the gifts given for the baby must be "respectfully returned."