The teenage girl was shot to death with an illegal handgun inside a home on Jamestown Crescent in Rexdale on July 9.
Toronto police are set to release more information about the two suspects and the charges they face at a Friday news conference.
Alicia Jasquith, Ross's mother, said she's aware of the arrests, but police didn't tell her who is charged or with what.
"It's far from closure," she told CBC News.
Jasquith said she plans to be in court when the accused appear.
In the wake of the shooting, police said they were treating the death as suspicious but also probing the possibility that the shooting may have been accidental.
Both the police and Ross's family appealed to the public for information about the gun, a .40-calibre short-barreled Smith & Wesson, came to be in the house.
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