Ihr can mean "her," but it cannot mean "she".
English distinguishes between "she" (subject/nominative case) and and "her" (object case--whether direct/accusative or indirect /dative). English uses one form for the nominative case (she) and the same form (her) for accusative and dative case.
German uses one form for both nominative and accusative cases (sie), but has a different form for dative case (ihr).
Masculine nouns have a distinct form for each of the cases (er/ihn/ihm). Neuter has two forms (es/ihm).
Ihr (in the sense of you all) has two forms: ihr for subject case, and euch for accusative and dative case. (Note that English has only one form "you")
It depends on the function of the pronoun in the sentence. As a subject, "Ihr" means "you all." As an indirect object, "ihr" means "her," as in Bob gives her the ball. If you want to say, "Bob gives you all the ball," you say "Bob gibt euch den Ball."
Ihr also has several other possible meanings, but I won't go into those here for lack of time.
Habt ihr Hunger? would be the proper way to say this. In the case of a question, the verb moves to the first position, with the subject typically following.