"Our happiness will be filled with concern until Gilad returns," his mother Aviva said, a day after Netanyahu said a deal had been made to free him in exchange for more than 1,000 Palestinian prisoners.
"It is clear that we won't be getting back the same boy. But the best professional people in Israel will be made available to help us," she said after she and her husband Noam met President Shimon Peres.
They did not take down the protest tent they erected more than a year ago to draw attention to their son's plight.
Shalit is expected to return to Israel within a few days, Netanyahu said Tuesday night, before the Cabinet voted in emergency session 26-3 in support of the swap.
All Israelis feel powerful emotions about Shalit, said Israel's ambassador to the United Kingdom, Daniel Taub.
"He really is the child of us all," Taub said, noting that almost all Israelis do military service.
"Seeing Gilad coming home ... is really coming home to every family. But at the same time it's very bittersweet," he said, since "every one of us in some way has been touched by terrorism."
Netanyahu said Tuesday that the government would "return Gilad healthy and whole to his family and all of Israel."
"The negotiations were difficult. ... We had to make difficult decisions but (the) correct one. With all the change taking place in the Middle East we did not know if a better deal or any deal would have been possible."
Netanyahu said on Twitter that the "arduous negotiations" brokered through Egyptian mediators resulted in a deal last Thursday and it was signed formally by Israel and the Palestinians on Tuesday.
In a speech broadcast on Hamas-run Al-Quds television, exiled Hamas leader Khaled Meshaal said the prisoner exchange will involve the release of 1,027 Palestinian prisoners, including women.
"The deal will happen in two stages -- the first stage the release of 450 Palestinian prisoners, including 315 Palestinian prisoners that have one or many life sentences and the ones who are with high sentences. The second stage will include 550 Palestinian prisoners," he said.
Hamas is the militant Palestinian movement that controls Gaza.
Of the 450 Palestinian prisoners to be freed during the first stage, 110 will go to the West Bank while 40 will go abroad, according to Mark Regev, Netanyahu's spokesman. The 550 prisoners scheduled to be released during the second stage will be freed two months later, he said.
According to Regev, jailed Palestinian lawmaker Marwan Barghouti is not among the prisoners Israel has agreed to release.
Palestinians captured Shalit in June 2006 after tunneling into the Jewish state and attacking an Israeli army outpost. Israel immediately launched a military incursion into Gaza to rescue Shalit, then 19, but failed to free him.
Since then, he has been held incommunicado by Hamas.
In October 2009, Hamas released a tape of Shalit to prove he was still alive in exchange for the release of a number of Palestinian prisoners being held in Israeli jails. Since then, there has been no proof of life.
There have been ongoing attempts to broker a deal to release Shalit, but all had failed.