Who would've known?

"Air you can breathe" she exulted. She feels as though she's standing at the end of the world, as though she's balancing in an edge and every single move counts. She couldn't see the horizon from up above the mountain. All she could see was a thick line of white clouds. She took small cautions step, she did not want to trip by the mini rocks around them.
Sarah, a 17 years old girl who wishes she had the world in her hand. She hates the beach, but stands in California with her toes in the sand. She has long curly hair, her skin tone is sun-tanned and a soft face like a 15 weeks baby born. Whilst there is Adam who is a very tall guy with a baby face that definitely doesn't match with his age, he reached the legal age few months ago. They've been friends since they knew their name. Despite that Adam is older than Sarah, the one who could handle all the responsibilities that would happen anytime and anywhere is obviously Sarah. Because she've been living with her mother only and she has no siblings. Her mother Lina would spend most of her times in her office (her job).
Sarah was drowning in school's assessments, tests, and homework. So Adam decided to take her out and surprise her because her birthday is near. And nothing from what Adam planned, happened. It all started with how Sarah's father treated her, and her mother.
Sarah's everyday routine was to see her dad act weird and strange everyday on a daily basis. She would ignore him and escape to Adam's house which is few block away. They spend their times watching movies mostly and talk about what they want to do in their future. They both had a very different mindset/perspective which made mostly everyone around them question "how did they got along?" But there is one day that was very odd, and she never imagined that it would actually happen.
30 June 2016, she entered the house to see her parents sitting in one table having their lunch as if nothing have ever happened, all the tears and the fights was only her hallucinating. But that happy moment didn't last for so long. She could hear something getting broken downstairs. Which she figured out, that now they're fighting and everything is normal now. She went downstairs ready to go to Adam's house, where it actually feels like home and she gets comfortable in. But her mum stopped her by calling her:" Honey, how are you darling?" She knew something was going to happen because this is not her usual mum. Her mum wouldn't ask about her. She smiled, faking her feelings saying I'm alright. 
Adam took her out, thinking that he will make everything alright but little does he know he made it worse. "SURPRISE! HAPPY BIRTHDAY TO SARAH." Her eyes started to tear with a frown on her face. "Today is my birthday and my parents forgot about it again for the third time."
Sarah went through a lot, and she had no friends only Adam who was always right next to her when she's in need. His family was like hers. She tried to replace them, but she couldn't. They were irreplaceable. She rushed out to the closest door and started running with her tears running down her face. She didn't know where she's going. It's like as if her legs are leading her to a place. She reached to a place that has a really high cliff and a fantasizing view.
Her mother, Lina received a call from an anonymous person saying "Is your child called Sarah?" she was in a complete shock, she didn't know what to do. Her husband came to her office which means he received the news too. Adam is left. This incident made them regret, more aware, less reckless. Her parents were so incautious to what they were doing. Little do they know they were drawing their daughter's path.
Who would've known that parents can be the reason to their daughter's suicide?