For the event, Markle wore a navy dress with a scooped neckline along with a navy jacket, and while there aren't many photos of the couple at the service, it's clear that Markle's baby bump has officially popped.
Prince Harry has met the Obamas on a number of occasions.
Meghan first wore the Mackage coat in Nottingham.
Over her seven years as Britain's Duchess of Cambridge, a sighting of Kate draped-in-diamond headwear was as rare as hearing her actually speak, but 2018 has been a year of change for the royal family and part of it means a more vocal - and dutifully dressed queen-in-waiting.
The event was publicised after the fact when Laura Hammond, professor of development studies at SOAS University London, tweeted: 'We had an excellent discussion about how research can tackle the problems of slavery and human trafficking.
During the event, Kate told the invited wives, partners, grandparents and children: "Not only are we grateful for you coming here to join our party, but also for the sacrifices you make on a daily basis on behalf of the nation".
Laura added a picture of Meghan at the head of the table.
In that speech, the Northwestern University alum announced two new grants for women for the University of the South Pacific and Fiji National University, perhaps a sign of the collaboration to come.
She said: "As a university graduate, I know the personal feeling of pride and excitement that comes with attending university".
She described the education of women and girls in developing countries as "vital", and called higher education's impact "incredible, impactful and pivotal".