Tracey Hepner, left, and her spouse, Army Brig. Gen. Tammy Smith. Hepner will sit with first lady Michelle Obama at the State of the Union address on Tuesday night. (Courtesy Tracey Hepner)

Tracey Hepner of Arlington, who co-founded the Military Partners and Families Coalition, a support group for LGBT military partners and their families, has been chosen to sit with first lady Michelle Obama during the State of the Union address Tuesday night, the White House said Monday.

Hepner works for the Department of Homeland Security as a master behavior detection officer, and she is married to the first openly gay or lesbian general in the military, Army Brig. Gen. Tammy Smith. They were married in the District last March.

Hepner, 50, said she got a call on Sunday and was “absolutely just thrilled.” She said she did not know if there were any specific reasons why she was chosen, other than having founded the military partners organization and being married to “the highest-ranking out military officer.”

She added, “Tomorrow night, I sit there representing all military families. We are a military family, we just happen to be gay.”

A White House official said the first lady’s box will include a variety of Americans whose lives would benefit from the policy proposals President Obama will announce Tuesday, including victims of gun violence, military families and those involved in immigration reform. The White House declined to be more specific on those proposals Monday.

This post was updated to include reaction from Hepner and a photo.