"Where is our grandmother?"
Translation:우리들의 할머니께서 어디 계세요?
계십니다 is a statement not a question. As it's in written form the question should be 계십니까? 계세요 is the spoken form. So it can use as a statement as well as a question.
I think this translate have a error. 우리들의 할머니는 어디 계세요? , 우리 할머니는 어디 계세요? are right translations.