It isn't just about Vada losing her peaceful youth, but also her little sister loses the relationship with her big sister. That's why it was great that this was shown at the beginning. And why it's so understandable that she keeps prodding at Vada for having a reaction.

Also her parents have to deal with this ultimate fear of nearly having lost their child. When the little sister remarks that the shooter followed Vada on Instagram so he must have known her (even though she didn't know him) it brings out renewed sobs from the mother: this brings the horror even closer to her child. Later in the film there's a line where Vada says 'what would you do without me' and her mother had to steady herself.