"Do you see her?"
Translation:Вы её видите?
Ты is the informal/friendly pronoun "you" and вы is the formal/respectful pronoun "you", as well as the plural "you" (implied as "you all", "y'all", "you guys", "all of you", etc).
Unlike many other languages, English doesn't distinguish between formal/informal "you". Therefore, the sentences have exactly the same meaning in English, unless there is evidence that the pronoun refers to a group of people, in which case вы is best translated as "you all". But be aware that when speaking in Russian people will get offended if you don't use the formal pronoun properly.