lizard monster protect family from grenade

A quirky, dysfunctional family's road trip is upended when they find themselves in the middle of the robot apocalypse and suddenly become humanity's unlikeliest last hope.

Father commits suicide with the girl and her younger sister by making them eat suicide pills because the beast are coming after them. However, the girl throws up the pill and survives to live with the lizard. Like the father said, the beast comes after the girl and asks whereabouts of her father.