An elderly fire victim whose home was torched after giving a group of teenagers water says she's praying they get the help they so desperately need.

The 88-year-old Ranui woman woke to find a couch on her front porch ablaze after she was targeted by three girls and boy who had knocked on her door late at night Sunday wanting water.

Out of kindness, she gave the teens a drink, but the group returned. When she turned them away two girls smashed a front window.

A couch was moved onto her front porch to cover the broken pane but things took a sinister turn a short time later when the pensioner woke to the blare of a smoke alarm and flames from the couch licking her house.

READ MORE: Teens smash window, torch elderly woman's couch after being given water

Police say the fire was deliberately lit.

Today the devout Catholic said rather than get angry at her teenage tormenters she was turning the other cheek and hoping they would be found so they could get much-needed help.

"I'm praying for them. I've asked my church and everyone I know to pray that the police will catch these children and they will get the care that they deserve.

"I'm not long for this world but these kids desperately need help."

The woman, who asked not to be identified, said since Sunday's nightmare, neighbours and friends had been towers of strength.

Everyone who lived near to her had assured they would be watching out for her and her home from now on.

"By the end of Sunday even new neighbours I'd never met came and told me their son had used the hose and put the fire out before the Fire Service turned up," she told the Herald.

"I'm surrounded by very good people.

"It just goes to prove there are a lot of good people in this world."

The woman reserved special praise for police who she said had shown her kindness and done everything possible to help her.

Police have described the arson as an "appalling crime".

"An innocent elderly victim was targeted in her own home, a place where she should have been able to be safe and feel safe," said Detective Senior Sergeant Roger Small.

"We know the Ranui community will be as horrified as we are by this incident and so we urge anyone with information to call police as soon as possible."