I've thought about this myself. If you were close to a situation and you knew things that bothered you - those things that point to "something's just not right" - and you had a grave concern about the honesty of the people you were close to, and whether they may have done something very bad, BUT you had no proof that could implicate them....
how long would you be able to process this "hinky" information you are faced with - maybe even first-hand! - without you wanting to talk to someone that could get it out. What are the police going to do if you walk in and share the behavior that is concerning you? the behavior you find suspicious? the family comments that reflect doubt on a certain member of the family?
...the answer is the police are going to do nothing. And still, you have this increasing mound of information that eats at you....like you're privy to an unacceptable situation, or a crime covered....or, just flat wrongness.
I'd find someone to talk to. I find someone who would speak for me.
While I absolutely agree that unnamed "anonymous" sources' information should be taken with a grain of salt, I also believe it's a fool's choice to completely dismiss them. There's some applicable box they most likely need to go in. Maybe "additional information for future reference".
As far as whether Debbie is being painted in good light or bad light, my heart doesn't leave much room for compassion when a person appears to do everything possible to rouse suspicion. Even severe OCD can't explain some of this.
Just my opinion.