Family friend, Simone Cameron, told SBS News that the two-year-old is now facing life without any front teeth until her adult set come in, which she said the family were told may not happen until she is seven-years-old.
Ms Cameron, who spoke to the family on Facetime at about 1pm on Thursday following the surgery, said they were worried about whether they would have access to soft food to feed Tharunicaa while her mouth healed.
"She won't be able to eat anything, I saw her little mouth and it was not looking good," she said.
"Priya [her mother] said that they'd had some troubles in the lead up to the surgery today because they had to apply for the special food that they want ... In the lead up to the surgery, here she is wondering if she will even be able to feed her daughter after the surgery."
Priya has reportedly been forced to chew the toddler's food before feeding her so she is able to eat it.
A surgery discharge report, seen by SBS News, confirms that the two-year-old underwent four extractions and four fissure seals.
At the time of publishing, her mother said Tharunicaa was still recovering from the anaesthetic, unsteady on her feet and very confused about what had happened.
The Australian Border Force (ABF) confirmed on Thursday that a child from the Broadmeadows Residential Precinct - located within the Melbourne Immigration Transit Accommodation Centre - was scheduled for surgery on 25 July at a Melbourne hospital.
The ABF spokesperson declined to comment further on the health of the child.
Two-year-old Tharunicaa is detained alongside her parents, Priya and Nades, and her three-year-old sister Kopika.
Fears for child asylum seekers held in Melbourne
The family, who are Tamil, have been in the centre for 17 months but previously lived in the small Queensland town of Biloela, where the community has launched an ongoing campaign to have the family returned home.
"It was very distressing for three-year-old Kopika, who could see her sister with this bloody and swollen mouth," Ms Cameron said.
"She was very upset, and Priya was pretty upset when I spoke to her today, it was a pretty big and stressful day. It all could have been avoidable."
It's the second time this month that Tharunicaa has spent time in a hospital, but an Australian Border Force spokesperson told SBS News the Department is "upholding Australia's human rights obligations by embedding the best interests of children into internal procedures and policies".
Just over two weeks ago, the two-year-old was taken to hospital and diagnosed with a mild head injury after a whiteboard in the centre's common room fell on her.
Following the incident, advocates claim that medical treatment was denied for over five hours and only provided when Tharunicaa began vomiting but the Department of Home Affairs disputes that there was any delay.
"Health care services for detainees and accompanying family are comparable to those available to the Australian community under the Australian public health system inclusive of mental health and dental care," the ABF spokesperson said.
As of June, at least five people under the age of 18 remained in immigration detention centres in Australia, all of them within the Melbourne Immigration Transit Accommodation Centre.
Victorian Commissioner for Children and Young People Liana Buchanan told SBS News earlier this month that "children should not be in detention", a position she said was in line with international standards.
"It's not appropriate for them and various UN instruments make that very clear," she said.
"Over some months now there have been a number of instances where at least two of the mothers of children in Broadmeadows have raised concerns about access to medical treatment [and] access to dental treatment in the case of one child.
"It's also the case that when I have met with those mothers they appear distressed and incredibly anxious about that prospect that when their young children need help, they are unable to get them that help."
Mr Dutton has previously claimed that no children remain in Australian immigration detention, with the Department of Home Affairs classifying the living arrangements of the family as within an "alternative place of detention".
Ms Buchanan, who has met personally with four of the five young people in the centre, said the claim that no children remain in immigration detention is categorically incorrect.