She was seen smiling and holding hands with Mr Trump as they boarded the Marine One on the South Lawn of the White House. The couple were later met with crowds of supporters at Nashville Airport.
The US president is due to face-off with Mr Biden at the Curb Event Center in Nashville later this evening.
The presidential candidate’s first debate was punctuated by frequent interruptions, mostly from Mr Trump, leaving the two men talking over each other and Mr Biden eventually telling the president to “shut up”.
A planned second debate did not happen after the president was diagnosed with coronavirus and he refused to participate in a virtual format.
Mr Biden and Mr Trump instead participated in town hall events on competing television networks.
After viewers complained about the number of interruptions during the first televised debate, the Commission on Presidential Debates announced this week that each candidate’s microphone will be turned off while his opponent gives a two-minute answer to an initial question on each debate topic.
After those initial replies, the microphones will stay on during open discussion, leaving it likely there will still be lots of crosstalk during rebuttals.
The debate will be moderated by NBC News White House correspondent Kristen Welker.
She will be the first black woman to serve as the moderator of a presidential debate since Carole Simpson in 1992.
The debate will be divided into six 15-minute segments, each on a topic selected by Ms Welker: Fighting Covid-19, American families, race in America, climate change, national security and leadership.
After he was diagnosed with Covid-19, Mr Trump has stressed that he feels “great” and his diagnosis was a “blessing in disguise”.
He continued to hold large campaign rallies and faced criticism from the government’s top infectious disease expert, Dr Anthony Fauci for hosting large gatherings.
Mr Biden, who has portrayed the Trump administration’s response as an abject failure, has taken a much more cautious approach.
The former vice president regularly wears a mask, holds small in-person campaign events and releases his Covid-19 test results, which so far have been negative.