Croatian authorities were still searching for the Englishman, who reportedly fled after the accident, the woman said.
Ms Ramage was rushed to hospital, where surgeons spent more than six hours working to re-attach her hand.
"The news and the headlines have been very upsetting and even though I'm not in contact with Amy's mother, I still feel very sorry for her,'' the woman said.
"Amy hasn't really spoken to anyone yet and she is the only person I would believe. I really think they have just got it all wrong.''
Ms Ramage's father, Reuben, and brother, Ben, had gone to Croatia to be with Amy.
"Hopefully, we can get to the bottom of what happened and find out the truth when Reuben comes back home,'' the relative said.
The New Zealand Embassy in Rome - accredited to Croatia - has been providing consular assistance to the Amy Ramage and her family.
This week police spokeswoman Marina Kraljevic Gudelj said police wanted to speak to the man who was with Ms Ramage so they could "clarify all the circumstances in this case".
Asked whether there was any truth to a suggestion that the pair had broken into the yacht, Ms Kraljevic Gudelj said she could not say.
"I also do not claim or deny whether there was any criminal suspicion in this case at all.
"We believe it was an unlucky accident, but want to check it all."
But she did confirm that the pair had earlier been on board another yacht, called Vaska, before being found on the yacht Anete, where the incident happened.
Meanwhile, doctors at KB Split Hospital, where Ms Ramage is being treated, said yesterday that she was recovering well. It was feared the graphic designer would lose her hand, but surgeons managed to save it during an operation that lasted six hours.
- with NZPA
