Attempts by the family to get the report from the police have been unsuccessful.
"I can't understand why we aren't entitled to see it. That's our daughter," said Trumpower, of Hagerstown.
Police officials said last week that the family - as well as the YMCA and the after-school group that sponsored the swimming outing - would ultimately receive the report.
Police Chief Dale J. Jones said Monday that he was not sure when the family would get a copy. He said he will look into the matter. Sgt. Rick Johnson, the lead investigator, was unavailable Monday afternoon.
The Herald-Mail filed a Freedom of Information Act request for the report on Sept. 18. Jones denied the request in a letter dated Sept. 26.
Kari Trumpower was one of a group of young members of Girls Inc. who participated in a regular swimming event at the YMCA on Sept. 11. At about 4:45 p.m. swimmers at a smaller pool were moved to the large pool when a YMCA class began, police said.
While Girls Inc. chaperones were outfitting the girls with flotation devices, a lifeguard saw Kari Trumpower beneath at least 4 feet of water in the large pool and dove in to pull her out, police said.
The youngster never regained consciousness and her parents authorized doctors to remove her from life-support systems on Sept. 17.
Police said last Thursday that they had ruled out any criminal violation in the death, but declined to elaborate on the details of the incident.
Many questions about the death, such why Kari was in the area of the big pool and how many lifeguards were on duty at the time of the accident, remain unanswered, Trumpower said.
"She would still be alive if there was somebody there," she said.
Lloyd Pearson, of Waynesboro, Pa., Kari's father, said he was told by police he would have a copy of the report by last Friday, more than two weeks after the accident.
"To me, the truth should come out right from the get-go, and why should it take so long?" he asked.
Trumpower said that when she tried to get a copy of the report Friday police told her it wasn't ready yet.
Staff Writer Brendan Kirby contributed to this story.