There are two different "have" verbs in English that are semantically distinct, but morphologically both similar. There is the auxiliary verb "have" that indicates the perfect aspect, and there is the main verb "have" that means "possess", as well as related meanings. Thus, one can say "Have you ever had a car?" where "have" indicates perfection and "had" is being used is the possessive sense. In the question "Has she any children?", "Has" is being used in the non-auxiliary sense, so modern English (at least, American English) requires that it have the auxiliary verb "do" placed in front of it to form a question. Having a bare "have" in a question or negation is archaic, but it survives in some places, such as the nursery rhyme: "Baa, baa black sheep, have you any wool?"