"She has seen the entire world."
Translation:Sie hat die komplette Welt gesehen.
For most German verbs, the so-called “weak” verbs, the past participle ends in ‘-t’. But for a minority of German verbs, the so-called “strong” ones, the past participle ends in ‘-en’. Strong verbs tend to be very common ones, such as ‘sehen’, and usually correspond to strong verbs in English; for example, the past participle of the English verb “to see” doesn't end in “–d” as weak English verbs do; it ends in ‘-n’: “seen”.
would "sie hat sich die ganze Welt angeschaut" also be a good translation?