1. Post selfies.

Apparently, the Queen herself is not a fan of selfies and looks down on the whole idea, according to the Mirror.
2. Go shopping by herself, or really do anything in public alone.

According to OK!, Meghan will have an all-female security team around her while she's out or performing royal duties.
3. Have her own social media accounts.

A few months before the royal wedding, Meghan closed all of her own social media accounts. But, according to ABC, Meghan, who was once very active on social media, had started to scale back her social media presence soon after her relationship with Harry became serious.
4. Vote in British elections.
The UK Parliament website says that, although it’s not against the law in Britain for royalty to vote, it is believed to be unconstitutional. Markle, who will not become a British citizen for a number of years, will also not be allowed to speak out on politics or social issues.
5. Wear bold-colored nail polish.

Apparently, the Queen is very picky about nail polish and prefers more delicate tones and translucent shades. According to Glamour, she has been wearing neutral shades since Harry proposed.
6. Sign autographs.

Meghan will not be able to sign autographs because it runs the risk of her signature getting forged.
7. Hit the sack before the Queen.

When Meghan and the Queen are staying in the same place, she will have to wait until the Queen goes to bed before she can go to sleep. It is "thought to be bad form."
8. Wear short hemlines.

Short dresses, short shorts and anything considered revealing are now banned for Meghan. In fact, she has been dressing much more conservatively ever since her engagement to Harry.
9. Show her bare legs.
Back in November – during Harry and Meghan's engagement photo shoot – Meghan was said to not be wearing the royal dress code, which according to one Royal expert, is "the only hard, steadfast rule in terms of what the Queen requires."
10. Sustain her career as an actor.
Markle, who starred in Suits for seven years, announced last November in an interview with Hello! Canada that she is foregoing her career saying, "I just see it as a change… It's a new chapter, right?"
11. Sit with her legs crossed.

According to the Sun, ladies are to sit with the ankles crossed or knees together to avoid any exposure of the crotch area. This is known as the Duchess Slant.