Due to the type of things that Lucius tends to deal with, there were a variety of potions in their cupboards in the kitchen, pre-brewed for all scenarios. Bellatrix already had an idea for how she would get wands for the boys without drawing the eye of the many who would not take kindly to seeing Bellatrix walking through the streets of Diagon Alley. She was excited about getting the boys" wands. So she quickly made her way to the room that Narcissa had often gone to sleep in when she was angry with Lucius. She found a few hairs on her bed and picked them up, then went to the closet and found some clothes. With an excited cackle, she made her way back to the kitchen to grab the polyjuice potion before changing into Narcissa's much larger clothes. She then ran to go find the boys.