06/05/2014 at 02:00 PM EDT
A 12-year-old girl stabbed 19 times by her two friends
in Wisconsin "is improving each and every day," her parents said in a statement on Thursday.
"Our little girl is a fighter," the parents of the victim, who was left to die in a Waukesha park, said, according to NBC News
. "We appreciate your patience, love and support, as we too are stunned and saddened by this tragedy."
Supporters also launched a fundraising campaign for the victim on Thursday and say she might need ongoing help for her psychological wounds.
"It's real early to say how long it will take her to get over this situation," family spokeswoman Dana Hoffmann tells PEOPLE. "It's a long-term healing process from a physical as well as mental and emotional standpoint of being so young and being betrayed by your two best friends."
The girl, identified by the initials PL in court documents, was allegedly stabbed by her friends after a weekend slumber party. She was found barely able to breathe
by a passerby who called 911.
The two girls, who have been charged as adults with attempted murder, told authorities the attack was inspired by a fictional online character known as Slender Man
The campaign aims to raise $250,000 through the Go Fund Me website
. Supporters in southeastern Wisconsin can visit a BMO Harris Bank branch and donate to the Hearts for Healing Fund. Hoffman says the family also needs funds for lawyers for undisclosed legal costs.
The victim's family also asks that supporters write the girl notes on purple hearts made from paper, fabric and felt. The parents will post the hearts on the girl's wall to remind her that the power of love is greater than all else, Hoffman says. Hearts can be sent to: Hearts for Healing, P.O. Box 407, Waukesha, WI, 53187-0407.
Hoffman says the victim's condition was upgraded Wednesday to stable, and she could be released from the hospital within a few days.