Although Israel has a mandatory draft at age 18, citizens such as Shamir, who leave before age 15 and relocate aboard, are exempt. They do their army service only if they return to Israel.
"In Israel, everyone is expected to join the army," she said. "But some who have moved to America no longer want to join the military, because they want to go to college. They have other options."
Shamir is one of about 200 a year who return from the United States to Israel to fulfill their army duty.
"I knew I would regret it my whole life if I didn't join the army," she said. "I wanted to be part of Israel and its people, and to give back."
Tuesday's award ceremony at the President's House will mark the 66th annual Israeli Independence Day and comes just weeks before Shamir turns 20 on May 31.
To be honored, soldiers had to be recommended by officers and reviewed by multiple panels of senior officers.
"Cpl. Shamir is receiving the award of excellency for her motivation and outstanding performance in her position," IDF spokeswoman Rachel Gordon said.
Shamir's parents, Tamar Barkan Shamir and Nir Shamir, flew from Newark, N.J., to Israel Friday to see their daughter receive her award.
"It's all been a very, very happy few days," Barkan Shamir said Monday from Tel Aviv, where her parents live. While she spoke on the phone, she said, she was watching her daughter carry the Israeli flag in a nationally televised ceremony featuring the honorees. Independence Day festivities started Monday.
Barkan Shamir, 46, works for Congregation Beth El in Voorhees as executive assistant to Rabbi Aaron Krupnick. She also runs Is Real, a company that organizes trips to Israel for families and couples, as well as bar mitzvahs and reunions.
Nir Shamir, 53, works for a high-tech Israeli company that relocated the family seven years ago so he could work in its Mount Laurel office. The couple will leave Israel on Wednesday to return to Voorhees.
Last week, Gov. Christie proclaimed May "Jewish American Heritage Month."
"Each May, we are reminded of the rich ethnic diversity in our state and the role Jewish Americans play in adding to that strong fabric," Christie said. "With one of the largest populations in the country, the New Jersey Jewish American community has enriched the social, cultural, and economic makeup of our state."
In New Jersey, 4.9 percent of the population is Jewish, according to an October 2013 report by the Pew Research Center's Religion and Public Life Project. Jewish households make up 2 percent of Pennsylvania's population.
Before graduating from Eastern High School in Voorhees in May 2012, Shamir was accepted at Pace University in New York City to study film editing. She deferred enrollment and may yet attend.
Instead, one week after graduation, she enrolled in Garin Tzabar, a program for those whose families live abroad who want to move back to Israel. She joined 26 young women from New Jersey, New York, Boston, and Philadelphia who also wanted to return to their homeland and serve in the army.
The women now live in a kibbutz in northern Israel. Among them is Gordon, 19, the IDF spokeswoman, who relocated from the Main Line and is Shamir's roommate.
Yael Shamir was drafted into the IDF in fall 2012 and enrolled in a four-month tank course. She learned how to drive, shoot, and navigate. Her commander choose her to specialize in tank simulators, which required a further four months of training. Simulators are used throughout the IDF as a cost-effective way to train soldiers without using real fire, according to the army.
From eight to 12 hours a day in one of the hottest regions in Israel, Shamir teaches combat soldiers in the 401st Armored Brigade to operate a tank in urban areas and open fields before they are assigned border patrol.
"When I do my job, I always think that I'm helping the soldiers defend themselves, which helps them defend the state of Israel, which is what we are all here for," she said.
Every soldier has 30 days off per year. Shamir takes her time in October to visit her parents in Voorhees. She has three brothers, two of whom live in Israel. Eitan Shamir, 23, graduated from Drexel University with a dual degree in chemistry and finance. He moved to Tel Aviv two months ago to work for a high-tech company. Guy Shamir, 21, is serving the final year of a four-year tour in the army and is based in central Israel. Tzur Shamir, 16, is a sophomore at Eastern.
Operating tanks was not something in which Barkan Shamir expected her daughter to excel.
"Yael is not a tomboy," she said. "She's a healthy, beautiful young lady. But she really is a very dedicated person and . . . once she decided to do it, she stepped up."
Women have a mandatory two-year minimum army service, while men have three. Shamir has served 18 months.
"This is really a great experience, and I'm learning skills - tools for life - that otherwise I wouldn't learn anywhere else," she said. "It's the best decision I've made in my life."