Without more identifying details, I can't tell which situation the question is addressing. I don't know the background, or what if any involvement she had in what happened. So, going on the general idea that it's a positive act to call for help when in a dangerous situation, I would say that her actions could qualify as heroic.
A man attacked his family, shooting and killing six people, four of whom were children. Another person involved in the incident was a fifteen year old girl who survived the ordeal by playing dead when a bullet fractured her skull. The man was seeking another family member and had intended to target more people, but was intercepted by police largely due to the fact that the surviving girl was able to call 9-1-1 after the incident. Her actions probably saved at least three more people.
She is a big hero. She was shot is the head and still managed to call the police to save her grandparents. She did a lot to help and saved lives. She did not have to do that. If she survives she should be rewarded for what she did to help.
The word hero has been used a lot in recent years to describe behavior that would have once fallen under the category of basic decency. This isn't exactly that type of case but the fact remains that it is heroic to leap on a grenade to save your platoon, or to run into a burning building to try and save the people trapped inside. Calling the police was a good thing to do, but it doesn't make the girl a hero.