A larger crowd of people remained outside.
The bodies of 12 people have been recovered and are at a mortuary, including one person who died after being taken to a hospital.
A separate protest occurred near the town hall offices.
"Everyone affected by this tragedy needs reassurance that the government is there for them at this awful time - and that is what I am determined to provide", she said.
"From a personal perspective, I really hope it isn't", Metropolitan Police commander Stuart Cundy said responding to speculation reported in The Telegraph and other media outlets that the number of dead could exceed 100.
Nadir, 24, who has friends in Grenfell Tower, said: "At least she (Theresa May) could've met the victims, (Jeremy) Corbyn was a good man. he came and met the people". While a small number of people have been identified, there is no doubt the number of dead will rise, say senior sources.
The criminal investigation will be centered on the type of cladding used when the building underwent renovations in 2015-2016 at a cost of £8.6 million ($11 million).
Meanwhile, experts have said sprinklers could have been fitted in the tower for £200,000, but Nick Paget-Brown, the Tory leader of Kensington and Chelsea Council, said there was not a "collective view" among residents in favour of installing them. This is an absolutely terrible fire that took place. "You get a lot of fragmentation of bodies, charring of bones and sometimes all that's left is ash", said Peter Vanezis, a professor of forensic medical sciences at Queen Mary University in London.
He also said survivors from the tower would be re-housed in the local area.
Choucair told Reuters residents had concerns about the safety of the building and she was angry about what has happened.
"She wanted an entirely controlled situation in which she didn't use her humanity", former cabinet minister Michael Portillo told the BBC.
She returned Friday to meet survivors, residents and volunteers at a local church - but faced cries of "coward" and "shame on you".
British newspapers, including those that backed May in the June 8 election, sharpened their criticism of the government.
"If there are other buildings which have that risky cladding then immediate action needs to be taken in a matter of weeks, or months - not in a couple of years", he added.
"That's one of the most awful things I have ever seen", Prince William said of the tower's blackened shell.
"What we are doing is putting in place the support that will help them". "It's an embarassment for all of them".
Argyll and Bute and Highland councils said they had no plans to review their properties, which are subject to regular inspections, but said they would follow any national guidance following the investigation into the London tragedy.
"We are in the richest borough in the United Kingdom and in this very borough we have a building where some of the poorest live and the safety measures are totally inadequate", said Mustafa Al Mansur, one of the organisers of the demonstration.
"They suspect it's a delaying tactic".