Judi James said she obviously just wanted to impress the Queen on their first solo appearance.
Meghan and the Queen arrived in Runcorn to open the new Mersey Gateway Bridge.
The 46-year-old created the silk crepe halterneck dress the American bride wore for her evening reception in Windsor last month.
Meghan, Duchess of Sussex attends a garden party at Buckingham Palace, in London Thomson Reuters LONDON (Reuters) - Britain's newest royal Meghan, the Duchess of Sussex, will join Queen Elizabeth on Thursday for her first official engagements without husband Prince Harry. This all took place in the grounds of the Catalyst Museum in Widnes.
"It does seem odd though, as normally the duchess would have been escorted around to her side of the limo and the door opened for her whilst [the queen] got in to her side, and they then drive away", Messervy added.
They were then able to replenish themselves by enjoying a lunch at the town hall.
The royal couple, now known as the Duke and Duchess of Sussex, will be making the tour around the time of the Invictus Games in Sydney, which is set for October 20-27.
In footage filmed by members of the crowd and shared on Twitter, Meghan can be heard speaking to a woman who asked her how she was enjoying her new life with Harry. "And keep in mind I've been working on my show for seven years", she told the BBC.
As they left, the Queen and duchess were presented with flowers by Savannah Cafferty, 11, and Alarni Wain, who was celebrating her eighth birthday.
During the visit to the bridge, the royals met architects, planners and community representatives and watched a performance from local schoolchildren before Her Majesty unveiled a plaque to mark the opening.