It's a time-honored tradition for the first lady to bring special guests to joint addresses made by the president before Congress. And it's also a tradition that those people represent the administration's agenda.

Here's who will sit with first lady Melanie Trump during President Trump's address on Tuesday night — and what that person's attendance may represent.

Megan Crowley

According to the White House, Crowley was diagnosed with Pompe disease at birth. The genetic disorder causes the buildup of a complex sugar in organs and tissues, impairing their function, according to NIH, and for infants, that can result in heart failure in the first year of life.

Crowley's father founded Novazyme Pharmaceuticals in order to look for a cure. Per Fox News, his company eventually helped develop an enzyme replacement therapy, Lumezyme. Crowley is now 20 and is attending Notre Dame University.

Crowley's family said on Facebook that they have a private meeting with President Trump.

The possible meaning? His plans for the pharmaceutical industry.

Jessica Davis, Susan Oliver and Jamiel Shaw Sr.

Davis and Oliver are the widows of Detective Michael Davis and Deputy Sheriff Danny Oliver Jr., two California police officers who were killed during a crime spree by an undocumented immigrant. According to reports, the man was deported twice prior to the slayings.

Shaw's son, Jamiel Shaw Jr., was shot in 2008 by an undocumented immigrant, who was a gang member. The teenager was a football star in Los Angeles.

The possible meaning? The need to deal with undocumented immigrants and, in Shaw's case, inner city crime.

Denisha Merriweather

Merriweather struggled with school as a child before moving in with her godmother and enrolling in the Florida Tax Credit Scholarship Program, according to the White House. She then attended a private school and became the first member of her family to graduate from high school and college.

The possible meaning? Support for school vouchers, of which Education Secretary Betsy DeVos is a proponent.

Maureen McCarthy Scalia

Scalia is the widow of the late Supreme Court Justice Antonin Scalia, who died in 2016.

The possible meaning? Reminding senators to move forward with Trump's own Supreme Court nominee, Neil Gorsuch, to fill the late Scalia's seat.

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