Hello,
now the logline is quite good to read, but I still miss the logic that links “the family disappearence” and the heist; I miss a clear inciting incident linked to a goal.
“When her family disappears,” can’t be the inciting event (I know from your previous explanation that this happened long before the story starts).

Act I.
A fraud investigator is doing his ordinary work, her life is a little sad because her familiy disappeared. Then something happens (inciting event), something that gives her a clear goal : ________________________.

For exemple : she finds out his father masterminded a big international heist. This gives her a clear goal : to find him and to find what happens to his family.

The logline maybe would be:

When a fraud investigator learns that her father masterminded an international heist, she must follow his tracks and solve the case to find her lost family.

Maybe it’s not perfect but here at least I see a clear path from beginning to end. Maybe to gain attention you should say what is this “heist”. You promise an international criminal heist : do not promise, prouve it! (at least, try). A fake nazi secret “degenerate art” collection for exemple? A fake Catherine de M?dicis’s jewel? It must be something big. If it’s a fake syberian gold pearl, ok but it’s not a big hook because nobody knows what it is and what is its value – anyway better to say what it is and let the reader judge if it’s a “international criminal heist”.

Anyway the message is focus about the inciting event and be specific.