PHOENIX (AP) — After wrapping up a hectic, two-day swing through Dallas, Houston and Phoenix to promote COVID-19 vaccinations, Jill Biden didn’t relax on the four-hour flight back to Washington.

She prepped for yet more travel in a week that by itself demonstrated the range of missions and emotions associated with the first lady's movements around the country.

Within the span of 36 hours this past week, Biden went from clinking cups of beer with Doug Emhoff, the husband of Vice President Kamala Harris, at an Astros baseball game in Houston to joining the president in Florida to comfort families whose loved ones were lost or missing after the Surfside condo collapse.

Along the way, she continued the juggling act that comes with being the first first lady to continue the career she had outside the White House. In Texas, she set aside an hour to Zoom into a book club meeting back in Virginia with women at the community college where she teaches English.

Jill Biden’s pace of travel is on par with the president's.

The week before her stops in Texas and Arizona, she pushed vaccinations in Mississippi and Tennessee, and again days later in the Florida cities of Kissimmee and Tampa.

Her stop at the Astros game was designed to help showcase a vaccination push by Major League Baseball that features incentives like tickets to future games and a replica World Series ring.

“It’s safe. It’s effective. It’s free,” she declared of the COVID-19 vaccines.

Jill Biden is spending most of the Fourth of July weekend appearing in Maine, New Hampshire and Pennsylvania at events celebrating progress on fighting the coronavirus.

“I think that we knew right from the start that she was going to be a more active first lady,” said Myra Gutin, who studies first ladies at Rider University in New Jersey. “She just personally strikes me as somebody that wants to be busy and somebody that wants to help.”

Jill Biden has said she doesn’t want to waste a minute of her time as first lady. She is logging more miles than some of her predecessors did at this point in their husbands' administrations, Gutin said.

Laura Bush, a former elementary school teacher and librarian, spent her initial months as first lady planning an education summit she hosted at Georgetown University in July 2001 and on supporting the No Child Left Behind education law, the first major domestic policy initiative of the new administration.

Michelle Obama used her opening months to visit Cabinet departments and thank federal workers for their service. Melania Trump lived at Trump Tower in Manhattan until son Barron finished the school year and they joined President Donald Trump at the White House in June 2017.

Anita McBride, a first lady scholar at American University, said Jill Biden came to the role well-prepared after being in the public eye for most of her adult life. Joe Biden was already a U.S. senator when they got married, and he was in Congress for a total of 36 years, followed by eight years as vice president.

Unlike Michelle Obama or Melania Trump, Jill Biden, 70, has no young children to command her attention. The first lady also likes to travel and stay busy.

It isn’t lost on the president just how busy his wife of 44 years is these days. He even suggested the stepped-up pace of White House life had cut into their “romantic time.”

“She’s been traveling all over the country. And doing major events for me … and for the country,” the president told Vogue magazine for a recent profile of his wife. “And so I’ll find that I’m working on a hell of an important speech and I’m distracted. And then I may not be working on one and I want to go and hang out with her, and she’s working on an important speech! Or grading papers.”

“We have to figure out a way, and I mean this sincerely, to be able to steal time for one another,” he said.

McBride, who was Laura Bush's chief of staff, said that while it's important for presidents to leave Washington and spend time among the people, they can catch criticism if they're seen as spending too much time traveling and not enough time taking care of the people's business.

“It's a balance for presidents to do both and a huge asset when the first lady can help,” McBride said in an email.

To that end, Jill Biden has become a top promoter of her husband's policies as well as her own issues and causes, ranging from child tax credits and a proposal for free community college to support for military families and finding a cure for cancer.

By Sunday she will have taken 20 solo official plane or car trips outside of Washington, including a handful of overnighters on the West Coast and in the Southwest. The count does not include her local stops in Washington or her trips with the president, such as last week's stop in Surfside, where she laid a large bouquet of white irises on the curb of a makeshift memorial near the site of the collapsed condo building.

Meanwhile, the president's trip to Michigan on Saturday will be his 21st aboard Air Force One for official business, including last month's trip to Europe. The count does not include Biden's weekends at his home in Wilmington, Delaware, or at the Camp David presidential retreat. It also does not include Biden's trip to Wilmington for a former staffer's wake, and a midweek getaway in June to his home in Rehoboth Beach, Delaware, for the first lady's birthday.

The first lady said she'll keep traveling around the country to encourage people, especially young people, to get vaccinated to help ward off COVID-19.

In Texas and Arizona, the first lady tried to cut through misinformation about the vaccines, assuring people that the doses are safe, effective and had been thoroughly tested. She stressed that the jabs are free, that people can get free rides to clinics and that appointments aren't necessary. She also noted that the shot itself is so quick, it doesn't hurt, and that she was vaccinated even though she hates needles.

At a clinic in an area of Phoenix where the vaccination rate is lagging, she made small talk with a girl as an alcohol pad was rubbed on her arm in preparation for the COVID-19 shot.

Then the vaccinator pushed the needle into the girl's arm, and pulled it out.

“It's over,” Biden exclaimed and applauded before she moved on.