Natasha/Yelena
As soon as she saw him attack her sister, Yelena ran up behind him. She threw her purse at him first which started him and then she jumped him. It wasn't easy in a straight skirt but she wasn't particularly worried about it, she managed to surprise him enough to get his attention and give Natasha time to regroup.
"I should have killed you after all, it seems," Yelea said as she punched him in the face. "Natasha, are you all right?" she cried as she hit Clint again.