Thank you for clarifying.She is mentioning things from the past "Closed Case" that were never even mentioned in court when she lost Custody of our daughter. Omsbudsman said my Ex should not know any of these details period. My Ex is blaming for Past and Present calls. Like I stated above, I have NOT made any calls to CPS for this new case against her.
So, you contacted CPS 6-7 years ago, and partially based on whatever was going on with Mom, there was a change of custody. That case is closed.
Mom now has a 3 year old, and there has been a report to CPS regarding that child. She occasionally says that you are the father. (I would certainly hope that there's 0% chance of that, given the past!)
During the course of the investigation of the current/active case, the investigator has mentioned the previous case involving your daughter, which is understandable if it's just in the context of, "Hey little lady, this ain't your first rodeo with us, so we're not inclined to give you the benefit of the doubt. Leopards not changing their spots and all." However, what you are saying is that there are more specific details, more along the line of, "You were reported several years ago by gonefishing for doing the same thing to your older daughter. Big surprise the dad is saying you're doing the same thing to this kid." Which Mom is latching onto and saying you tattled on her.
Yes, it's good to report such slips, because it's wrong and very unprofessional. People may be less likely to report abuse if they fear the abuser is going to do something to them.
However, unless you filed a false report all those years ago, consider this: your daughter is safe, but this 3 year old is not. The only place Mom should be complaining is at the image in the mirror. Don't respond to her garbage. Block her if necessary. Remember: this woman has likely abused at least 2 children, and is not the most honest person - she's certainly not honest with herself.
If she persists, and crosses the boundary of annoying to threatening, you should consider is a restraining order. (Different states have different standards for what rises to the level of justifying a restraining order. I don't know CA's, and I have no idea whether she has crossed that boundary.)