LYNNFIELD – A couple argued over how to name their unborn child shortly before Joseph Cummings, 51, shot and killed Kimberly Nguyen, 35, and her sister, Lilly, 29, before killing himself Monday night, according to Essex County District Attorney Jonathan Blodgett.”Our investigation indicates there was an argument over the name of the child she was carrying. She wanted to hyphenate the name; he did not,” said Steve O’Connell, Blodgett’s spokesman.Stephanie Nguyen, Kimberly Nguyen’s 12-year-old daughter from a previous marriage, hid in one of 39 Ledge Road’s bedrooms – where the killings occurred – until the shooting stopped. Police received a 9:58 p.m. call about the shootings.”She was frozen in fear and didn’t move until after the last shot, then she fled to a neighbor’s,” Blodgett said during a press conference at the Lynnfield Police Station.Kimberly Nguyen’s friends on Tuesday described the woman as a hard-working small-business owner who looked forward to the birth of her second child and died at the hands of a man she had been involved with for eight years.Blodgett said the couple did not have a history of domestic violence complaints or restraining orders, but Cummings was named in two domestic violence incidents – one in East Boston in 2003 and another involving a Saugus woman in 1998.Kimberly Nguyen’s relatives and friends threw her a baby shower last Sunday. Sometime between that party and the shootings, Cummings, 51, and Nguyen, 35, argued.Stephanie Nguyen, a Lynnfield Middle School student, was in the care of her father, Tony Nguyen, by noon Tuesday after spending some time Tuesday morning with a cousin or aunt.”She is quiet, very quiet, but OK,” Nguyen said during a phone interview.Lynnfield Superintendent Robert Hassett said Nguyen is in the seventh grade and formerly attended the Huckleberry Hill School. School administrators notified teachers about the incident by handouts and e-mail at 7:15 a.m. Tuesday and made school counselors available to children.”We tried to make it as normal a school day as possible,” Hassett said.Blodgett said preliminary investigations indicate Cummings shot Kimberly Nguyen at least once in their second-floor bedroom. Lilly Nguyen, 29, jumped out a second floor window in an adjoining bedroom and Cummings spotted her and shot her before shooting himself.Police recovered .45-caliber and .357-caliber handguns from 39 Ledge Road and Lynnfield Police Chief David Breen said other weapons were taken by police from the house. Blodgett said the handguns were not licensed.Breen said no domestic violence reports were filed with Lynnfield police on Cummings or Kimberly Nguyen and said no complaints were received from neighbors.But Blodgett said Cummings, during the two years he lived with Nguyen in the home she bought in 2004, exhibited behavior that caught the attention of his half-dozen neighbors on semi-rural Ledge Road, where woods hem in large lawns.”There was some indication neighbors were concerned, but no calls had been made about his behavior,” the DA said.Breen said a former neighbor told him Monday night that Cummings’ decision to erect a fence between his property and Nguyen’s surprised him.”He was very protective of the property,” Breen said.A hand-lettered sign on Nguyen’s East Boston nail shop, House of Nails, read, “salon closed until further notice.”Friends and customers, including Michelle Johnson of Revere and Siobhan McKenna of Winthrop, lit candles in front of the closed shop Tuesday afternoon and left bouquets.”She was an awesome business woman. She was so loved in East Boston and she was known as the best nail person,” McKenna said.McKenna and Lisa Martello of Winthrop worked at House of Beauty, a salon they said Nguyen opened in Winthrop. They said she also opened another nail salon in East Boston and said Lilly Nguyen worked in House of Nails. Blodgett said Lilly Nguyen was a 2006 Wesleyan University graduate who wanted to be a doctor.McKenna said Kimberly Nguyen had descri