At the Festival of Remembrance Service at Royal Albert Hall on Saturday, the royal couples marked their first public appearance as a foursome since their family playdate at a polo match in July.
But, Kate and William may have sparked further complications after posting a series of pictures of last night's service on their Kensington Royal Instagram account.
The Royal Family were positioned in order of precedence, with the Queen sat in the centre of the front row.
During a surprise visit to military families in Windsor, Berkshire this week, the Duke and Duchess of Sussex chatted with parents about maintaining a household with only one parent present, with Harry, 35, specifically asking about the challenges of having a second child.
The Royal British Legion Festival of Remembrance marks 75 years since notable battles of 1944, which included Monte Cassino, Kohima and Imphal, D-Day and the collaboration of Commonwealth and Allied forces.
It also celebrated the 100th anniversary of the Government Communications Headquarters, and was a tribute to RFA Mounts Bay, which this year delivered supplies and aid to the Bahamas after Hurricane Dorian.
The event is held the day before Remembrance Sunday to commemorate all who have lost their lives in war. The Queen was accompanied by Prince Charles' wife Camilla and Kate on one balcony; in previous years, Prince Philip has joined the event, but in his absence, Kate took his place, just as she did last year.
On Sunday, while the Queen watched the Remembrance Day service from the balcony, Prince Charles laid a wreath on her behalf.
Harry recently opened up about the rumored rift between him and his older brother in ITV's documentary Harry & Meghan: An African Journey.
"But look, we're brothers".
But another told how Prince William was "furious" with Harry for giving the interview and had told him so.
"You know, we don't see each other as much as we, as much as we used to because we're so busy".