Pearl remains in Radius Rimu Park, in Kamo, which offered two weeks of free care after learning of her plight.
Insurance will now cover the rest of her stay until she can move back into her renovated home.
Nephew Ray Broad was "bloody glad" police had finally tracked down someone but said it did not take away the trauma Pearl had experienced.
"She desperately wants to go home. It's been a big upheaval for her and something she didn't need at this age."
Mr Broad estimated it would take builders at least six weeks to complete the necessary work before Pearl could move back home.
"It's a massive job to repair the house. It needs a new roof as the fire got up in the ceiling.
"It needs to be recarpeted and repainted. It's all going to take time," he said.
Most items in the house would have to be replaced after a bed was set on fire and slowly smouldered, filling the house with smoke and resulting in a thick layer of soot covering most surfaces.
A television was stolen and about $140 cash was taken from a moneybox as well.
Mr Broad was overwhelmed by the public response and offers of help, and had tried to thank as many people as he could in person.
The Northern Advocate co-ordinated an appeal for Pearl and editor Craig Cooper said he hoped in some way, the public reaction to Pearl's plight had helped find who was responsible.
"The public's reaction creates that little extra pressure, that what happened was especially unjust, and who knows, it might have even helped identify who was responsible."
