Distraught youngsters left scores of bouquets and balloons for the 16-year-old, named locally as Jodie Muir, after her death at the weekend.
Police Scotland said it was still unclear whether Jodie, believed to be from the East End of Glasgow, died as a result of taking drugs or from natural causes.
Dozens of her friends left floral tributes, teddy bears, and touching messages about Jodie at the
gates of her school, Eastbank Academy, in Shettleston.
A huge cardboard sign was left among the tributes to allow friends to leave messages of condolence and the makeshift shrine continued to grow throughout yesterday.
The schoolgirl died in her home at around 5am on Saturday after coming back from a house party in Rutherglen on Friday night.
Relatives denied Jodie took drugs and it was suggested there is a heart condition in her family.
Police now want to trace around 50 youngsters who were also at the party.
Chief Superintendent Ciorstan Shearer said: "I know that this is a very painful and upsetting time for the girl's family and friends. Police Scotland will do all that we can to support her family at this difficult time.
"I do not yet know whether or not drugs have played a part in this tragic death, and it is therefore important to trace other partygoers to establish that they are safe and well.
"At this time we know that there were around 40 to 50 other teenagers at this party in Rutherglen and we have managed to speak to a significant number of them.
"It is vital however that those who have not already spoken to police, come forward as soon as possible."
Police confirmed further tests are now being carried out in a bid to establish the exact cause of death.