In photos obtained by Mail Online, Meghan sips from a coffee mug as she drives along the Los Angeles roads.
The former Suits actress was wearing a white baseball cap and dark, oversized sunglasses.
Meghan won’t be joining Harry in the UK, with the Duke of Sussex having already made his way back home to the States.
During his brief visit, Harry did not meet up with Prince William or his wife Kate Middleton, who is recovering from her own surgery.
Charles’ cancer diagnosis sent shockwaves on Tuesday, with the Palace announcing the the discovery was made while the King was having treatment on an enlarged prostate.
The Palace said: “During The King’s recent hospital procedure for benign prostate enlargement, a separate issue of concern was noted. Subsequent diagnostic tests have identified a form of cancer.
“His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties.
“Throughout this period, His Majesty will continue to undertake State business and official paperwork as usual. The King is grateful to his medical team for their swift intervention, which was made possible thanks to his recent hospital procedure. He remains wholly positive about his treatment and looks forward to returning to full public duty as soon as possible.
“His Majesty has chosen to share his diagnosis to prevent speculation and in the hope it may assist public understanding for all those around the world who are affected by cancer.”