There's a thing called singular they, though... https://en.wikipedia.org/wiki/Singular_they?wprov=sfla1
I think that it is great in context, but in a simple sentence such as this one, adding "they" would cause some notable confusion. We add this kind of translation to sentences like "If someone wants to ask, they ask" to make it clear which verb ending matches singular and which matches plural.
This construction θέλει να takes the "subjunctive." ρωτήσει is aorist subjunctive (also called past subjunctive), which the following blog that discusses the matter calls "simple past subjunctive": https://blogs.transparent.com/greek/the-subjunctive-mood-in-modern-greek/ It is a good idea to get a grammar to help out with subjunctive as an introduction to aspectual differentiation. Mackridge, The Modern Greek Language (Clarendon: Oxford, 1985) discusses the varied uses of να on pp. 282-98. DL discusses the matter here: https://forum.duolingo.com/comment/24471413/A-Guide-for-the-Greek-Subjunctive-Active-Verbs Dimitri writes that the past subjunctive "expresses non-continuation. Τhe action expressed by the verb is not ongoing or the speaker is not interested in the duration of the action."