Now Playing: Inside Meghan Markle and Princess Kate's friendship

Now Playing: See the carriage route Prince Harry and Meghan Markle will take on the big day

Now Playing: How Meghan Markle channels Princess Diana's humanitarianism

Now Playing: How Meghan Markle will carry on Princess Diana's legacy

Now Playing: Female trumpeter to make history at Harry, Markle wedding

Now Playing: Will a music legend perform at the royal wedding?

Now Playing: Markle follows in footsteps of royal brides Diana, Kate

Now Playing: Backstreet Boys return with new song and summer tour dates

Now Playing: Meghan Markle's dad will not attend royal wedding

Now Playing: How Walt Disney World creates magical and memorable weddings

Now Playing: Terry Crews reveals his dream cast for an all-black superhero squad

Now Playing: From Diana to Meghan: What it takes to dress a royal

Now Playing: Thomas Markle admits staging photos with paparazzi

Now Playing: 'The Americans' star on shooting the 'heartbreaking' final scene and what's next

Now Playing: 'The Americans' star forgets the words to this classic nursery rhyme

Now Playing: Justin Timberlake surprises 88-year-old superfan

Now Playing: Morena Baccarin opens up about 'Deadpool 2'

Now Playing: Behind the scenes of Netflix's '13 Reasons Why'

Now Playing: Harry, Markle name bridesmaids and page boys

Now Playing: Markle's father to undergo heart surgery: Reports