Translation:My little sister did all of the exercises and went to bed.
Shouldnt it be всё and not все? She even pronounces it as всё so I dont get why its written differently
I only used the word 'the' in my translation because it was there among the multiple choice words, even though the sentence felt just as natural to me without it - I've learnt the hard way on DL's multiple-choice questions that if such a word is included in the options, they nearly always want you to use it, even if the English sentence would be equally correct without it!
Well, yes and no. весь/вся/всё/все is the nominative form of that word which is basically an adjective. Adjectives in Russian decline with case, number and gender of the nouns they modify. So like you see, всю ночь is actually accusative (ночь is feminine, всю is the accusative form of вся).