Transcript for Princess Diana would have wanted her children to 'marry for love': Part 2

Reporter: Princess Diana and Meghan Markle. Before they were world famous, they were young girls playing dress up. Never imaging their futures as real, live princesses. It's really hard not to draw parallels between Meghan and Diana. They both have this fantastic way of connecting with people. Having this, sort of, magical touch with people. ??? You're so gorgeous it actually hurts ??? Reporter: So much alike and yet worlds apart. From age two until she was around six Meghan lived here, in this apartment above a garage, with her mother Doria pictured here on Instagram, in the middle class miracle mile neighborhood of los angles. Meghan is the world's most famous valley girl. She was the product of a white, caucasian father and an African American mother who was a yoga teacher and a social worker. She went to private schools. Went to a private girls catholic school for high school. Reporter: And after school Meghan would often visit her father on the set where he worked on the long-running t-v show, "Married with children." On the set of "Married with children" every day for 10 years I was there. Wow. I know it's a very perverse place for a little girl to grow up. I mean, Diana's childhood was totally different to Meghan's. Diana lived in park house, next door to the queen's home of sandringham in Norfolk. She had nannies. She had tutors. Reporter: Diana attended a girl's boarding school in Switzerland and had dreams of being a ballet dancer. Meghan was the bright girl in class. She says she was smart. She liked debate. She liked protest. She was articulate. Reporter: Andrew Morton interviewed princess Diana for his book, "Diana: Her true story." Diana, as she said to me, you know, she was no great shakes academically. She was very shy. Her idea of torment was having to go onstage in the Christmas play. Reporter: A far cry from Meghan who jumped at the chance to act in school productions at immaculate heart school in los Angeles. But whether Diana wanted to or not, at 20 she was thrust onto a global stage. 750 million people watched as she walked down the aisle of St. Paul's cathedral to marry prince Charles. Escorting Diana was her father Earl Spencer, still recovering from a stroke. And just this week the question of who will walk Meghan down the aisle has become front page news. This morning kensington palace announcing that Meghan Markle has asked prince Charles to accompany her down the aisle. Reporter: And when she does walk down the aisle it will be as a new kind a princess. Had a career by her 30th birthday Meghan was starring as a wise-cracking paralegal in the television series "Suits." Wow you're pretty good. You've hit on me. I wasn't hitting on you. Trust me I'm not interested. Reporter: She had married her long-time boyfriend, a movie producer named Trevor Engelson. Diana, at 30, had two young children and a crumbling marriage which would end in divorce. Divorce runs through the royal family now like a tide. Three out of four of the queen's children got divorced. As a result, there is now more leeway in the royal family. William and Harry are allowed to marry women they love. Reporter: And while Diana was Reporter: And while Diana was to able escape her unhappy marriage, tragedy would strike shy of Harry's 13th birthday. We have an update on the condition of Diana the princess of Wales who was involved in a car accident. Diana princess of Wales has died. Tragic death almost exactly 16 hours ago of Diana. It's still hard to comprehend the extent to which princess Diana's death affected, not just people in Britain, but around the world. Reporter: Patrick Jephson was princess Diana's chief of staff for eight years. 21 years since that terrible day I have been constantly struck by wherever you go people will remember where they were when she died. Reporter: The world mourned watching her devastated sons follow Diana's coffin through the streets of London. I think losing your mother at such a young age does end up shaping your life massively. Of course it does. For generations, royalty has held themselves in privacy. And here, Harry has talked openly about the loss of his mother. Reporter: Prince Harry revealed his feelings in a recent bbc documentary entitled, "Diana: Seven days." I think one of the hardest things to come to terms with is the fact that the people that chased her through -- into the tunnel were the same people that were taking photographs of her while she was still dying in the back seat of the car. Anybody who has experienced the loss of a parent at that sort of age would understand that the world can seem a very strange place and in some respects the intensity of grief and loss has a desensitizing effect. Reporter: But he would soldier on. Following royal tradition Harry joined the army. He became a combat helicopter pilot and he would serve two tours in Afghanistan. Life in the army, as he has said, was very formative and gave him a sense of structure when he needed it. Discipline when he knew he needed it. Reporter: Meghan would divorce her husband after only two years of marriage. Meanwhile Harry watched his oldeiam marry Kate Middleton and start their family. The three were often together at polo matches and doing charity work. He was always the third wheel on royal enjoyments. It was always the three of them on events and he didn't have anyone by his side and that began to matter. I've longed for kids since I was very very young. So I'm waiting to find the right person, someone who is willing to take on the job. Reporter: And though the woman who is now taking on that role will never meet her mother-in-law, prince Harry has said that his mother Diana would most certainly approve. There is no doubt that princess Diana would have wanted her children to marry for love. Being royal can be very lonely and she would have wanted for her children somebody who could be a companion and an encouragement and a source of wisdom for them.

This transcript has been automatically generated and may not be 100% accurate.