Ms Markle's mother, Doria Ragland, will meet the Queen for the first time at Windsor Castle later, accompanied by her daughter and future son-in-law.
Ms Ragland has already been introduced to some of the Windsors - including Prince Charles and Prince William.
It remains unclear who will walk Ms Markle down the aisle of St George's Chapel, as her father will not attend.
Ms Markle released a statement on Thursday confirming her father would not attend the wedding and saying she hoped he could be given space to focus on his health.
Ms Markle and Prince Harry were in Windsor on Thursday to prepare for the big day.
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