Lam, accompanied by Education minister Kevin Yeung Yun-hung and Home Affairs chief Lau Kong-wah, held the meeting on Monday with the youngsters, mostly in their 20s and 30s, who did not appear to have any political affiliations, the South China Morning Post reported.
An informed source said the meeting was initiated by Beijing's liaison office.
The meeting took place two months after university student unions rejected Lam's offer to have a dialogue with her amid the political crisis that has engulfed the city since June.
Hong Kong has been roiled by protests sparked by the government's now-abandoned plans to pass a bill that would allow criminal extraditions to mainland China.
Even though Lam has declared the bill "dead", defiant protesters have raised five main demands, including the formal withdrawal of the legislation and an independent judge-led inquiry into police actions.
According to the source, some attendees at the Monday meeting told Lam that it was not necessary for her to satisfy the five demands all at once. But she could consider completely withdrawing the bill first and establishing the independent inquiry.
Also on Monday, Terence Mak Chin-ho, the assistant commissioner of police in charge of operations, defended an officer who made headlines when he fired a warning shot during Sunday's violent protests in the city's Tsuen Wan area, saying at a press briefing that he acted with courage and restraint.
They also criticised protesters for using deadly weapons and acting with intent to kill one of their officers who had fallen to the ground.
Late Monday, a group of protesters gathered in Sham Shui Po and shone laser pointers at the police station but were quickly dispersed by officers in riot gear, reports the South China Morning Post.
On Sunday, officers fired 145 rounds of tear gas, 50 rubber bullets and 13 sponge grenades to disperse protesters in Tsuen Wan.
Fifty-four protesters, aged 12 to 51, were arrested on suspicion of taking part in an illegal assembly, assaulting officers and being in possession of offensive weapons, among other actions.
Sixteen officers were injured, including one who was stabbed in the back by a sharp object.
He remains hospitalised.
( With inputs from IANS )