(CNN) Did you know you can donate your frequent flyer miles to help reunite families who were separated at the US-Mexico border?

After a viral tweet this week from a woman who donated her miles, people have now donated more than 7.3 million frequent flyer miles to a non-profit organization whose main focus is reuniting families separated by political conflicts around the world.

"My husband travels a lot. Downside: he's gone a lot. Upside: frequent flyer miles. We just used some to fly a 3-yr-old and his dad, who had been separated at the border, from Michigan (where the son had been taken) to their extended family," University of Michigan professor Beth Wilensky tweeted.

My husband travels a lot. Downside: he's gone a lot. Upside: frequent flyer miles. We just used some to fly a 3-yr-old and his dad, who had been separated at the border, from Michigan (where the son had been taken) to their extended family. DM me if you have miles to donate. — Beth Wilensky (@bethwilensky) August 6, 2018

The US government has separated more than 2,500 children from parents at the border since implementing its "zero tolerance" policy, and 559 of those children remain in custody, the Department of Homeland Security confirmed last week.

People have been stepping in to help separated families, and Wilensky's tweet highlighted another way to contribute.

Read More