"He was really nice, really polite, and a loving father," she said. "He just doted on his children."
Ms Gray said Mr Rope and his partner often separated but always reconciled.
The pair were teenagers when their daughter was born but were mature parents, she said.
"They really loved each other but sometimes they just got on each other's nerves, like most young couples. They would split up and have time apart [but] they always got back together."
Ms Gray said Mr Rope's partner planned to return to Wanganui with their 5-year-old daughter and 1-year-old son.
It is believed Mr Rope was charged with drink driving on Thursday night.
Inspector David White said police were investigating Mr Rope's movements in the hours before his death.
"We're interviewing those who have been in contact with him in the last few days to try to establish where he's been, what he's been doing, what he's been thinking."
Officers arrived at Mr Rope's home before 10am after reports of a firearm being discharged.
Surrounding streets were cordoned off as negotiators tried to make contact with him and police used teargas in a failed attempt to force him from the house.
Officers found his body shortly after 2pm.
A Defence Force spokesman said it was not known whether the gun involved was a military or privately owned weapon.
Major Robert Loftus, chief of staff of 1st Brigade, said the army was supporting the soldier's family.
"Our thoughts are with the family, friends and colleagues of the soldier concerned at this difficult time.
"The NZ Army will be providing appropriate support to the family."
Mr Rope was not deployed overseas during his service in the army, Major Loftus said.
Central District Police Manager of Operations Inspector Dave White said police were "saddened that there wasn't a different outcome".
The incident had been referred to the coroner.
Alexander Rope
* 23
* Went to Wanganui High School
* Two children: a 5-year-old daughter and 1-year-old son
* Family live in the Wanganui area
* Never deployed overseas during military service