The pope was unhurt in the dramatic attack in St Peter's Basilica, while a prominent French cardinal was among others who fell in the confusion and was hospitalised with a broken hip.
The Vatican said the woman tried a similar manoeuvre at the Christmas Eve mass one year ago but was stopped by security.
Maiolo, who has Swiss-Italian nationality, told doctors she "did not want to hurt" the pope, La Repubblica newspaper reported.
Vatican spokesman Federico Lombardi said the Vatican judicial system was "generally very lenient."
While the assault raised questions about Vatican security, Benedict spoke confidently when he appeared again for his Christmas Day "Urbi et Orbi" blessing to tens of thousands of pilgrims massed in St Peter's Square.
He made an appeal to "abandon all logic of violence and revenge" and choose the "path of peaceful coexistence."
Benedict spoke out on the plight of migrants, saying: "In the face of the exodus of all those who migrate from their homelands and are driven away by hunger, intolerance or environmental degradation," the Roman Catholic Church calls for "an attitude of acceptance and welcome."
The leader of the world's 1.1 billion Roman Catholics also said society remains "deeply marked by a severe economic crisis" and "the painful wounds of war and conflict."
Benedict XVI went on to give traditional blessings in 65 languages.
The attack came amid concerns about the pope's health, fuelled by a Vatican decision to move Thursday's mass forward two hours before the traditional midnight hour due to the pontiff's advanced age.
Relieved applause broke out in St Peter's Basilica when the pope got back on his feet within moments of the woman leaping over a security barrier and grabbing his robes near the neck, pulling him to the floor.
Several other people also fell, including French Cardinal Roger Etchegaray, 87, who broke his hip and will have to undergo surgery, the Vatican said.
Cardinal Angelo Bagnasco, archbishop of Genoa and head of the Italian bishops' conference, played down the incident. "Nothing serious happened. It was a woman who tried to greet the holy father," he was quoted as saying by La Repubblica.
The Vatican later named Maiolo and said she had been hospitalised for "necessary treatment."
Vatican spokesman Lombardi also shrugged off the incident, while praising the pontiff's "great self-control".
He added: "It was an assault, but it wasn't dangerous because she wasn't armed."
Lombardi said protecting the pope from all risk by creating a wall between him and the faithful would be "unthinkable."
The Christmas Eve mass is one of few occasions when tourists and pilgrims can get close to the pontiff.
Papal security has been tightened since Mehmet Ali Agca, a Turk, shot and nearly killed Benedict's predecessor John Paul II in St Peter's Square in 1981.
Thursday's incident occurred less than two weeks after a man said to have mental problems attacked Italian Prime Minister Silvio Berlusconi in Milan, breaking his nose and two teeth with a souvenir model of Milan's cathedral.
"We must really put a stop to this machine of lies, extremism and hatred," Berlusconi, who is still recovering from the attack, told Italian television in an interview when asked about the assault on the pope.
Benedict has had no notable health problems since his 2005 election apart from a fractured wrist from a fall in July while on holiday.
Four years before he became pope, however, then Cardinal Joseph Ratzinger spent nearly a month in hospital following a brain haemorrhage, according to the German daily Bild. It said he has since suffered from fainting spells.
--------------------------------------------------------------------------------------------------------