Let our Tav try to administer potion, but let it be "too late"...
She dies instantly. It's already too late from the moment she started running. The main character trying to shove an antidote down her throat at that point would only make us look silly

[quote]Let our Tav to offer her parents last conversation with her.
Impossible to do since Kagha says to bury the child away from sight. So she probably gets dumped somewhere where the sun doesn't shine.
Let our Tav to waste revivify scroll, since her afterlife would be quite fine compared to this existence ...
I don't like when gameplay logic is being used for story logic.
As far as story goes, revive scrolls do not exist within it. They're just gameplay items used solely for the convenience of the player to revive companions. Same as Withers, who has an interesting backstory but in all honesty is just a revive bot.
Otherwise every peasant would be trying to revive their dead ones in the story. Look at through how much hell Mayrina went to "revive" her dead husband and how that turns out. And look at what happens to Astarion and Lae'zel if they die due to story decisions. Once you're dead, you're dead for good. No resurrections.