Questions & Answers about Hace media hora que ella investiga el decorado.
This is a very common Spanish structure for saying that something started some time ago and is still continuing now.
Hace + time expression + que + present tense
So:
Hace media hora que ella investiga el decorado
means roughly: She has been investigating the set for half an hour.
Literally, hace means it makes or it has been, but in English we normally translate the whole structure as for or has been ... for.
Because Spanish often uses the present tense where English uses the present perfect continuous.
In English, we say:
She has been investigating...
In Spanish, with this time-expression pattern, it is normal to say:
Hace media hora que investiga...
So even though the Spanish verb is in the present, the meaning is still an action that began in the past and continues now.
This is one of those places where Spanish and English do not match tense-for-tense.