Nouel Alba, 37, had initially pleaded not guilty to wire fraud and making false statements but she changed her plea Thursday in federal court in Bridgeport, the Hartford (Conn.) Courant reported.
Court documents and statements in court indicated Alba used Facebook, as well as email, text messages and telephone calls, to try to pass herself off as an aunt of Noah Pozner, 6, one of 26 students and staff who were killed Dec. 14, 2012, in the massacre at Sandy Hook Elementary School.
Federal prosecutors, citing a person Alba contacted with an appeal for donations, said Alba collected funds through a PayPal account after claiming she "had to go to Sandy Hook Elementary School and enter the crime scene to identify her nephew for law enforcement personnel."
Kimberly K. Mertz, FBI special agent in charge of the New Haven division, said in a statement Alba's actions "caused undue sadness and harm to those already suffering and to those involved with running legitimate and caring charities."
Alba, who is scheduled to be sentenced Aug. 29 on the federal charges, faces state charges in New York, the newspaper said.
Adam Lanza killed his mother at their home before going to the school, where he took his own life after killing 20 students and six staff members.