"We were hoping against all hope that she would be coming home," she said. "But as time went on it became clear something wasn't right."
Speaking to The Daily Post yesterday, Ms Donlan said her sister was a wonderful person who would be greatly missed by a lot of people.
"She did not deserve this. She was taken away from us far too young, she still had a lot to do on this earth."
The death had hit Ms Hoffman-Tamm's family and partner hard, although they were all "hanging in there".
"Her partner is very fragile. They had been together about 14 years and had a loving relationship."
Ms Donlan, who spent the afternoon with her sister the day she disappeared, said her younger sister was the most non-judgmental person she had ever known.
"She never judged anyone. She befriended people from all walks of life ... the elderly, young, disabled ..."
Ms Hoffman-Tamm was born in Rotorua, attending Glenholme School and Rotorua Girls' High School, and had lived in the city most of her life. She was well known around Glenholme and being a sickness beneficiary hadn't stopped her contributing to her community, her sister said.
"She was always helping people out, mowing their lawns, etc," she said. "She would give anybody the shirt off her back."
Ms Donlan said she was relieved an arrest had been made in connection with the case but was unable to comment further.
Forensic examination of a Holland St address continued over the weekend and was expected to continue today. A police team has also been searching the Rotorua Landfill for "items of interest".
Meanwhile police are still appealing for sightings of a two-tone light-coloured Subaru Legacy between the evening of Wednesday, November 7 and Sunday, November 11 in Rotorua and between Rotorua, Whakatane and Murupara. They also want to hear about any suspicious behaviour in the Holland St or Victoria St areas during that time. Call Rotorua police on (07) 349 9400 or anonymously via Crimestoppers on (0800) 555 111.
Ms Hoffman-Tamm's funeral will be held on Wednesday at 1.30pm at Osbornes Funeral Home.