Melania Trump has cancelled plans to accompany her husband to a rally in Pennsylvania on Tuesday night, citing "an abundance of caution" and a lingering cough following her coronavirus infection.
The first lady, 50, was expected to return to the public eye for the first time at the event.
She has not been seen since the White House confirmed her October 1 positive test for coronavirus.
"Mrs Trump continues to feel better every day following her recovery from COVID-19, but with a lingering cough, and out of an abundance of caution, she will not be traveling today," her spokesman said on Tuesday morning.
Unlike her husband, she did not need to be admitted to hospital when coronavirus was confirmed as her symptoms were mild.
Donald Trump, 74, spent three nights at the Walter Reed medical center, receiving a powerful and experimental cocktail of steroids and antibodies, plus being treated with oxygen.
He was said to have been admitted to hospital "out of an abundance of caution", but it later emerged that he needed oxygen to help him breathe before being admitted.
He himself has confessed that he was feeling "not too hot" on the day of his transportation to Walter Reed.
He returned to the White House on October 5, and has been at pains ever since to show how vital and energetic he is - returning to the campaign trail with gusto, dancing on stage, and telling aides he wanted a rally a day across the country with two weeks remaining until the election.
Mrs Trump, by contrast, has taken a low-key approach to recovery, issuing a statement last week saying that she had chosen to treat her symptoms of fatigue with vitamins and fruit rather than drugs.
She also confirmed that their 14-year-old son Barron tested positive too, but he was unaffected by the virus - news that came as little surprise, given his age.