On Monday morning, Chief Health Officer Doctor Jeanette Young said further testing had revealed she caught the virus from another traveller in hotel quarantine.
"The good thing is we know the lady, who came from Portugal, has the B 11-7, which used to be called the United Kingdom variant", Dr Young told reporters.
Queensland Health confirmed on Sunday night the woman did not have the highly contagious Delta variant, as initially feared.
The same worker then went to a higher floor and swabbed the flight attendant.
"We know the lady went into Cotton On at the DFO", Dr Young said.
"The lady from Portugal has then ended up with exactly the same virus as the gentleman from Mongolia".
All staff members at the Four Points Hotel are being retested.
'We are thinking that through fomite transmission, that staff member has transported the virus from the gentleman to the lady'.
A man aged in his 60s returned a positive result after visiting the Portuguese Family Centre at Ellen Grove in Brisbane on Saturday.
He was there at the same time as a flight attendant who authorities believe contracted coronavirus while in hotel quarantine and tested positive after she was released.
The flight attendant was also out in the Brisbane CBD between 5pm and 6pm, and anyone in the city between that time is being asked to monitor for symptoms.
Queensland authorities believe the risk posed by its latest case of community transmission is low.
"There is no doubt that she has acquired it in the hotel, or at some point when she's come into contact with that person", Young said.
Dr Young expressed optimism that risks from the new infection were low.
She said the woman was also outside in the city from 5pm to 6pm and travelled by a private auto to the Portuguese Family Centre from 7pm until 7.50pm.
The transmission of Covid-19 at a Brisbane hotel that infected a flight attendant could be a "world first", according to Australia's chief medico.
'Overnight there's been two new exposure venues in Canberra.
"If you are from Queensland, it is probably best not to travel to NSW at this time".
Dr Young said health officials were still working through CCTV footage to work out the exact shops the woman visited.
Ms Palaszczuk said if they were able to get the one community case under control over the next two days the government would be in a position to ease restrictions from 1am on Friday. Victorians must still complete a travel declaration but will not be required to hotel quarantine.