Councillors have no power over demolition/building permits. Building permit staff have no power to deny the permit if all requirements are met. It sounds like she was made aware of the permit (that's what the motion is about, making sure councillors are aware) and started the process to see if it should be designated, however the developer started demolishing much quicker than anticipated. The only thing that can stop it is City Council passing a motion to give notice of intent to designate the property. Next meeting is not until February 10, although a special meeting could be called if enough councillors are on board.
Here is the timeline:
Jan 7 - Demolition Permit application submitted
Jan 12 - Letter submitted to Toronto and East York Community Council from KWT requesting staff review potential to designating the building heritage
http://www.toronto.ca/legdocs/mmis/2015/te/bgrd/backgroundfile-74715.pdf
Jan 13 - Toronto and East York Community Council approved KWT motion.
http://app.toronto.ca/tmmis/viewAgendaItemHistory.do?item=2015.TE3.100
Jan 16 - Demolition permit approved
Jan 17 - Demolition commences