Her family said they hadn't been able to get in touch with her since the attacks on the weekend.
"We love you and we miss you dearly", they said.
An online fundraising campaign, originally set up to collect money to send Ms Zelenak's parents to the United Kingdom, has been re-opened in light of the confirmation of her death.
The body was recovered near Limehouse in east London, downstream of London Bridge. Boden wrote. "At risk of sounding cliche, life is short and we should all use the time we have wisely".
Her aunt, Tara, spoke on behalf of the family yesterday, saying, "The family is trying to keep it together but bracing for the worst obviously".
The man who tried to save Australian nanny Sara Zelenak as she was stabbed by terrorists in London has revealed he is haunted and can not sleep after the harrowing attack.
Women place bouquets of flowers on a memorial for victims at London Bridge.
Canadian Archibald, 30, was the first victim to be named.
The names of the victims will not be released until the government has received official confirmation of the identities and the families have been notified.
According to the document, Sydney has been in close contact with all the victim's families.
Prime Minister Malcolm Turnbull said he had spoken to Ms Zelenak's family.
"We are heartbroken by these awful crimes and by this bad loss", he said in an interview with 3AW today.
"This is heart-rending, this is the last thing anybody expects to happen to their children when they are in London".
Wisconsinite Steve Stricker in position for weekend berth at Erin Hills
Open, mainly because they couldn't keep it out of the thick fescue that frames the wide fairways at Erin Hills. Fowler dropped to a share of fifth at six under, alongside compatriots Jamie Lovemark and JB Holmes (both 69).
MISSING: Sara Zelenak is missing after the London Bridge terror attacks.
"We are facing a global threat", he said.
"It is a disease and it is corrupting, seeking to destroy from within the Islamic religion and of course, lashing out to destroy and undermine our way of life".
It was unclear whether Boden was killed at London Bridge or during the rampage that followed in the Borough Market area.
"Sara is absolutely attractive".
Gerard Vowls was in Borough Market in Saturday night when the horrific massacre unfolded and witnessed the jihadis set on the 21-year-old from Brisbane.
Moments later the 47-year-old construction worker said he spotted a "blonde girl", who he later identified as Ms Zelenak, set upon by Youssef Zaghba, Khuram Butt and Rachid Redouane.
She had been with a friend, Pri Goncalves, 26, when the two heard the white Renault van crash on the bridge.
Seven people were killed in the terror attack on Saturday night.
"We were counting down the days to see her", Ms Wallace told Brisbane radio station 97.3FM.
"The one with Ariana Grande's [concert], she was going to go to the concert".
James McMullan, 32, from Hackney, was last seen outside the Barrowboy And Banker pub and his sister said police have told her his bank card was found on a body at the scene of the attack.
Mayor Karen Williams said it was hard to understand how terrorists could have such a willing hatred of life and called on all Redlanders to support the family.