Is a mother who died in a car accident—and was observant of religious duties—considered a martyr, and will her soul meet the souls of the children who died with her in the accident in Barzakh?

The person who dies in a car accident is hoped to be a martyr because he is like one who dies by demolition, and the souls of the dead meet in the Barzakh (interim realm). The Muslim children who die before puberty are in Paradise and under the care of Abraham, peace be upon him. There is a Hadith concerning them: "Their little ones are the da‘amees (small, active fish) of Paradise; one of them will meet his father and take hold of his garment, and he will not let go until Allah admits him and his father into Paradise."