Learn Spanish (Latin America): Es probable que ella no evalúe el presupuesto hoy. - It is probable that she will not evaluate the budget today.

The phrase es probable que (it is probable that) is an impersonal expression showing uncertainty. These types of expressions require the verb that follows them to be in the subjunctive mood. Since evaluar is an -ar verb, its "she" form in the present subjunctive ends in -e, making it evalúe.

Why does evalúe have an accent mark on the "u"?

In the verb evaluar, the spoken stress falls on the "u" in most present tense and present subjunctive forms. To show that the "u" and the "e" are pronounced as two separate syllables (eh-bah-LOO-eh) rather than blending into one sound, a written accent mark is required on the "u".

The English translation says "she will not evaluate," but isn't evalúe present tense?

Yes, evalúe is the present subjunctive. However, in Spanish, the present subjunctive is frequently used to talk about things that might happen in the future. Because phrases like es probable que already show we are guessing about an upcoming event, the present subjunctive naturally translates to "will" in English.

Do we have to include the word ella in this sentence?

You don't strictly have to, but it is very common and helpful here. In the present subjunctive, the "I" form and the "he/she/it" form are exactly the same (evalúe). Including ella prevents confusion and makes it perfectly clear that we are talking about her, rather than "I" or "he".