What Spell Does Mrs Weasley Use On Bellatrix?

What Spell Does Mrs Weasley Use On Bellatrix? ‘Yes, the last and worst. Avada Kedavra … the killing curse. ‘ Molly used Petrificus Totalus, the body binder spell, hence the fact Bellatrix was frozen, then she used a strong exploding spell, probably Reducto or Diffindo, whch destroyed Bellatrix. Do any good characters use Avada Kedavra?