Hannah Anderson tells of her ordeal on ask.fm, and says her abductor got what he deserved when he was killed in shootout

A 16-year-old Californian girl who was kidnapped by a close family friend suspected of murdering her mother and eight-year-old brother says the man threatened to kill her if she tried to escape and got what he deserved when he died in a shootout with authorities in the Idaho wilderness.

Hannah Anderson went online barely 48 hours after her rescue on Saturday and started fielding hundreds of questions through a social media site. Many were typical teenage fare – she likes singer Justin Bieber and her favourite colour is pink – but she also answered queries about how she was kidnapped, survived captivity and how she is dealing with the deaths of her mother and brother.

The postings started on Monday night, hours after her father publicly requested that the family be allowed to grieve and heal in private. Brett Anderson didn't respond to a text message seeking comment about his daughter's postings, which continued into Tuesday evening.

Police have said little about their investigation. Jan Caldwell, a spokeswoman for the San Diego county sheriff's department, said authorities are aware of the online comments but could not confirm the account was Hannah's.

The postings appear on the ask.fm social-networking site account for "Hannahbanana722" of Lakeside, the San Diego community where the teenager lived with her mother and brother. At one point during the lengthy series of posts, a questioner asked Hannah to post a photo and she complied. The image shows her with a wide smile.

Dawn MacNabb, whose son Alan is one of Hannah's closest friends, confirmed the postings were by the teenager. Alan spoke on the phone with Hannah on Tuesday and urged her to delete some of the postings, MacNabb said.

"He said she was going to, but I don't know if she will," she said.

The teenager declined interview requests from news organisations that posted to her account.

She was kidnapped on 4 August by James Lee DiMaggio, 40, her father's best friend, who invited the children and their mother, Christina Anderson, 44, to his house in Boulevard, 65 miles (105km) east of San Diego.

"He told us he was losing his house because of money issues so we went up there one last time to support him, and to have fun riding go-karts up there but he tricked us," Hannah wrote.

She said DiMaggio tied up her mother and brother in his garage. Their bodies were found after a fire destroyed the home. She said she didn't know they had died until an FBI agent told her at the hospital after her rescue on Saturday.

"I wish I could go back in time and risk my life to try and save theirs. I will never forgive myself for not trying harder to save them," she wrote.

She said she "basically" stayed awake for six straight days and DiMaggio ignored her requests for food. She couldn't try to escape because DiMaggio had a gun and "threatened to kill me and anyone who tried to help".

She said she was too frightened to ask for help when four horseback riders encountered the pair in the remote wilderness on Wednesday. The riders didn't report the sightings to police until the next day, after returning home and learning about the massive search spanning much of the western United States and parts of Canada and Mexico.

"I had to act calm I didn't want them to get hurt. I was scared that he would kill them," she wrote.

Asked if she would have preferred to see DiMaggio get a lifetime prison sentence instead of being killed by FBI agents, she said: "He deserved what he got."

Hannah acknowledged being uncomfortable around DiMaggio even before the ordeal, saying he once told her that he was drawn to her.

"He said it was more like a family crush like he had feelings as in he wanted nothing bad to happen to me," she wrote.

She said she didn't tell her parents because DiMaggio was her father's best friend "and I didn't want to ruin anything between them".

She said she anticipated returning to El Capitan high school.

"I'm just still shocked and this (whole) thing seems unreal," she wrote.