Queen Elizabeth II
Queen Elizabeth II has a very important role at Prince Harry and Meghan Markle's royal wedding. Pictured: Queen Elizabeth II is seen at the Chichester Theatre while visiting West Sussex on Nov. 30, 2017 in Chichester, United Kingdom. Getty Images/Stuart C. Wilson

Queen Elizabeth II will have an important role in Prince Harry and Meghan Markle's royal wedding.

The Queen will be present at Prince Harry and Markle's nuptials. She will witness her grandson and the "Suits" actress' exchange of vows. But aside from this, she is expected to be a significant person at the event.

"I'm told from my sources at Windsor Castle that [Queen Elizabeth] is being very, very accommodating," royal biographer Katie Nicholl told Entertainment Tonight. "She has said to the couple, 'This is your wedding, this is your day. Plan it as you want it.' [This] is very generous because, don't forget, the queen is opening up her home."

"Don't forget she's hugely close to her grandson. They have a very special relationship. She is thrilled to be seeing Harry settle down and finally marry," Nicholl continued. "She's going to want to be a very important part of that day and indeed she will."

However, the author suggests that Queen Elizabeth II might skip a part of Prince Harry and Markle's wedding. The "Harry: Life, Loss and Love" author believes that the monarch will not attend the evening reception.

"I think when it comes to the evening reception and certainly the party, if the Spice Girls are performing then, I don't think the queen's going to be on the dance floor," she said.

Queen Elizabeth II and the rest of the royal family members are expected to arrive at St. George's Chapel as early as 6 a.m. to 6:20 a.m. E.T. Bustle suggests that the Queen will be in her seat before the ceremony starts.

On Prince William and Middleton's royal wedding, Queen Elizabeth II arrived with Prince Philip, Prince Charles and Camilla Parker Bowles. She will likely arrive with the same company too.

When Her Majesty arrives, fans will likely see her grand entrance. The royals will reportedly use the Windsor Castle's Long Walk so the public can see them. However, the groom, Prince Harry, and the best man, Prince William will use another path. They will enter the church through a side entrance at the West Steps.

Prince Harry and Markle's wedding ceremony will begin at 12 p.m. UK time (7 a.m. EST). After an hour, the couple will leave the venue for their carriage procession.