Is it permissible for a woman to kill herself if she knows that she cannot escape a powerful gang that has surrounded her with the intent of raping her, in order that they not violate her honor?

A woman is not permitted to kill herself if she is besieged for rape, because preserving life takes precedence over preserving honor. Harm is not removed by harm; rather, the lesser of two harms is committed to ward off the greater. And killing oneself is a great harm.