Translation:We are going to assume that she ate.
I agree with cghoyt, but I think "We are going to assume that she has eaten" is better English. I frequently wonder whether such sentences that sound slightly odd in English are also slightly odd in Spanish (and just an artifact of the machine process), or do Spanish verb tenses work differently than English ones.
On the other hand, if the act of eating were more specific, it would be natural to say, "I am going to assume that she ate the candies."
Patrick is coming to the point here. Different languages use the grammatical studies in different ways. Where one uses imperfect/simple past in Spanish is not the same as in English (or French or German). "has eaten" is the more accurate and correct English translation if this particular sentence, even though it uses a different grammatical structure.
Are you asking what's wrong with "We are going to assume what she ate" ? I could be wrong but this is what I think: In this sentence "que" is a relative pronoun ("that", or in a different context, "which"). For my interpretation of your sentence, the Spanish would be "Nosotros vamos a asumir lo que ella comió" ( literally ..."that which she ate"). (When I entered this into google translate, it returned "We are going to take what she ate.")
According to the Royal Spanish Academy (la Real Academia Espanola) here are the accepted definitions of the verb "asumir" 1. tr. Atraer a sí, tomar para sí. 2. tr. Hacerse cargo, responsabilizarse de algo, aceptarlo. 3. tr. Adquirir, tomar una forma mayor. While it would include the English version of the word "assume", as in "He assumed the throne", it would not include the mental activity of taking something in account, or previous knowledge, just as "He assumed that I knew his name" or "I assumed that she had already eaten". If I am wrong, please correct me. But that's the way I learned use of this verb in particular.
In this sentence, que is "that" as a conjunction: "We are going to assume that she ate." Eso/esa/ese are used both in the sense of an adjective, such as "She ate that apple", and as a pronoun, as in "She ate that" (with whatever "that" was usually mentioned before or afterwards).
Duolingo, this is what you've dragged me down to: Looking up the word "that" in an English dictionary!
This seems like it would be subjunctive, because when you're assuming "that she ate", that's not a certain thing. Instead it is a supposition, which I thought is what the subjunctive tense is used for. So I would think that even though "asumir" does not need any conjugation because it would stay in the infinitive, comió (preterite, él/ella/usted) should instead be comiera (subjunctive imperfect, él/ella/usted). Can anyone help me with this?