She didn't want to eat, my translation is "non vuole mangiare", which is wrong. The answer given is "non vuose mangiare", which I haven't encountered till now. Is it a new tense? And why my answer is wrong? Grazie mille.
"Non vuole mangiare" is wrong because it is present tense, whereas "she didn't want to eat" is simple past.
However, "Vuose" is not an Italian word. What you are looking for is the word "volle", the 3rd person singular of the passato remoto tense of the verb "volere".
So, the correct translation for "She didn't want to eat" is:
Non volle mangiare.
If you need help with Italian tenses, I usually recommend this resource to my students: ITALIAN VERBS
"She didn't want to eat" is Simple Past, which in Italian is translated with either Passato Prossimo or Passato Remoto of the Indicativo form. You translated it with a Presente, which would be translated to "She doesn't want to eat."
The correct translations are "Non volle mangiare" or, the more frequently used, "Non ha voluto mangiare".