"Mi tía comerá pescado esta noche."
Translation:My aunt will eat fish tonight.
It does in the present tense, but not as much in other tenses. The future progressive (mi tía estará comiendo) does not mean quite the same thing as the simple future (mi tía comerá).
For example, "My aunt will be eating dinner when you call" is very different from "My aunt will eat dinner when you call." The first means that you will be interrupting her dinner by calling, while the second means she will start eating once you call.
When it's simply "tonight," the difference is more about tone than actual meaning, but it's still there.