After her teenage sister commits a sudden suicide, an anxiety-disordered young woman returns to her childhood home and begins to discover family secrets that lead her to investigate the tragedy.

DPG specified a fundamental problem with the concept and if you are re working the concept best to start with this problem.
Is this story about her dealing with her sister's death or about her stopping the sex trafficking ring?

I find the later more interesting as it has far more potential for plot development.

Thanks for your input everyone! The suicide does lead the main character to begin looking into her sister's life. She discovers that her sister was living a secret life as part of an online sex trafficking ring that could have landed her in trouble, putting the "suicide" in question. I'm going to rework this thing now!

As written the logline suggests two inciting incidents: 1] the suicide. 2] the discovery. Only the latter leads to the main plot line: investigating the tragedy. IOW, taking this logline literally, if there was a suicide -- but no discovery -- would the sister investigate her sister's death?

Or is the story line that the suicide itself triggers the sister into investigating the tragedy -- and as a result of that skeletons start falling out of the family closet?

>>sudden suicide
Independent of ideation, the act itself is often impulsive so it is sufficient to just say "suicide".

>>anxiety-disordered
Why not grief-stricken instead? Then there would be a more emotionally direct cause-and-effect relationship between the suicide and going home. [The surviving sister's own disorders could be a complicating factor in the story and the grief could compound her mental affliction.]