If you are referring to Bellatrix Lestrange, Molly Weasley hit her with a nonverbal curse after she nearly killed Ginny and she died. If you are referring to Bella Swan from Twilight, go on twilight answers! http://twilightsaga.answers.wikia.comHo/wiki/w_does_bella_die_or_does_she_%3A
Bellatrix had been battling Ginny, Luna, and Neville all at the same time but their powers equaled her own. Her killing curse nearly missed Ginny by half a inch causing Harry to change targets and come after her furiously, although Molly reached her first. "Not my daughter, you Bitch!" she cried out before battling her. All throughout the battle, Bella taunted Molly, thinking that there was no way she would overpower her. Molly's nonverbal curse hit her squarely in the chest and she died with the ghost of her laughter still on her face, only realizing what had happened at the last second, just like her cousin Sirius, who had been murdered by none other than Bella herself 2 years ago.