The two royals just had their first joint outing together, without any other royals around, as they toured a campus of King’s College in London. Queen Elizabeth and Kate Middleton greeted officials as they arrived on campus to open up newly renovated learning facilities at the school to be named Bush House. According to reports from People, they also watched a robotics demonstration that showed a robot conducting surgery (most likely not on a grape, though) and witnessed students running the Entrepreneur Institute's “virtual trading floor."
The first official solo outing with the monarch is a rite of passage of sorts for the Duchesses who have become a part of the royal family over the last decade. Although the Duchess of Cambridge has been a part of the family since 2011 when she married William, she and her mother-in-law somehow never got around to taking a solo outing together without any other royalty around. The same can't be said for Meghan Markle, who had her first solo outing in June 2018, about a month after she married into the family. The one thing both Duchesses have in common with regards to this instance, however, is their choice in outfits. For both solo outings, Queen Elizabeth II wore a brightly colored suit (green for Markle, pink for Middleton), and each Duchess erred on the side of wearing muted colors to downplay any attention brought to them with Her Majesty present.
Surely one can imagine that this is not the very first time Queen Elizabeth II and Kate Middleton have been alone in a room together as the only royals around. In fact, according to People, the two have had at least one private moment in the past: they met up in Buckingham Palace to take a look at the Duchess of Cambridge's wedding dress in 2011 before the ceremony took place at Westminster Abbey.