Elba Marquez said her granddaughter, Ana Grace Marquez-Greene, had been enrolled at the Sandy Hook Elementary by her parents because the school had a good reputation.
- Connecticut school shooting victims named
The family had moved to Connecticut after the girl's mother was hired to teach at a local university, Elba Marquez said.
Relatives confirmed the girl's 9-year-old brother, Isaiah, was also at the school during Friday's shooting, but was not injured.
Some family members from Puerto Rico are expected to fly to Connecticut on Saturday for the girl's funeral.
The father of the two children, Jimmy Greene, is a U.S. jazz musician who was a faculty member at the University of Manitoba's school of music for three years before his family moved to Newtown.
His family was reached by phone on Friday. They told CBC News that one of the children, a boy, was fine, but would not confirm the status of the girl.
Winnipeg musician Steve Kirby, who is close friends with Greene's family, described the children as "really bright" and talented.
"Beautiful children, picture-book children, and obedient and spiritual. You know, the kind of kids you want moving in next door," he said.
Edmund Dawe, dean of the Faculty of Music at the University of Manitoba, said that Ana was "just a sweetheart."
"I remember just a very bright, vivacious, talented young lady who had so much potential," Dawe said.
Whyte Ridge Baptist Church, a Winnipeg church that the family used to attend, held a vigil to honour Ana's life on Friday evening.
Terry Janke, the church's senior pastor, told CBC News that Greene confirmed Ana's death to a congregation member.
"Through these times it rocks anybody's world, losing a child, and so we're holding ourselves up in grief, but holding them up that their faith be unshakable," Janke said.
Janke said many of the children at the Whyte Ridge church quickly became friends with Isaiah and Ana, and some continued their friendships as penpals after the family moved to Newtown.
"Ana was just a sweet little girl," he said. "I mean, she just had a big smile on her face."
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