Considering the members of her family who have been assisinated while being PM it makes sense to me.
MSNBC - Gandhi allies: She no longer wants to be PM: "Chatterjee said Gandhi would later explain why she does not want to become prime minister.
'There are rumors that her children are against her becoming prime minister, maybe because of security reasons, he said, adding that she was buckling under pressure, due to fears for her children."
-- It would have been an interesting difference in India going from a Hindu nationalist party member being PM to a woman who was born in India being PM. It's going to be an interesting few days.