Best friend

So there is this girl in my class, lets call her X and we have been best friends since sixth grade (we are currently in 8th grade. And i have seen several signs of her being depressed, like she draws lots pictures of blood with words that she says she has been called. She also has been a lot quieter lately and i feel like we have become distant I might be stupid but if something is wrong i want to help her, but she hardly opens up and i don’t want to ruin our friendship...