Harper was named to the team, along with teammates Kaela Davis, Rebecca Greenwell, and Taya Reimer.

Taya Reimer suffered an ankle injury in the game against Guam, and was unable to play in the remainder of the competition.

On the second day, the three remaining players won their first two games, then managed to beat the Czech Republic in two overtimes.

This left them scheduled to play Japan for the bronze medal, but with only two players, the team forfeited due to injury.

[2] Harper was named to the USA Basketball U16 team, which competed in the Second FIBA Americas U16 Championship in 2011, held in Mérida, Mexico.

The win secured the gold medal for the competition, as well as an automatic bid to the Second FIBA U17 World Championship For Women – 2012 held in Amsterdam.

The USA team won all eight contests to win the world championship and the gold medal for the event.

Harper competed on behalf of the US at the Tenth FIBA U19 World Championship, held in Klaipėda and Panevežys, Lithuania, in July 2013.

Harper scored 8.4 points per game and recorded 18 steals, only one fewer than team leader Morgan Tuck.

The USA responded with an 11–2 run with foul shot contributions by Jefferson and a three-point basket from Stewart.

After the injury the US extended the lead to 18 points and ended up with a 93–77 win, good for first place in their group.

Cuba missed its final shot to give the USA the win 65–64, propelling them into the gold-medal game against Canada.

[9] The gold-medal game matched up the host team Canada against USA, in a sold-out arena dominated by fans in red and white and waving the Canadian flag.

However the Canadians, spurred on by the home crowd cheering, fought back and tied up the game at halftime.

[10][11][12][13] Harper was named to the USA 3x3 national team which competed in the twenty sixteen World Cup held in Guangzhou, China, October 11–15, 2016.

In the SEC Tournament, the team made it to the finals, but fell short by a single point to Tennessee 71–70.

Despite being only 5' 8", she averaged 7.1 rebounds per game, good enough for seventh place in the SEC and the only player in the top ten under six feet tall.