Hang on guys, not so fast....
Lets look at this again. OP said that they DV'ed a LAW FIRM....not the debt buyer. If the same law firm represents the CA in this case, then you could have a case against the law firm, but not against the plaintiff. If the law firm representing the plaintiff is not the same one that the OP sent a DV letter to, then there is no violation at all. Remember, a DV to a collector is not binding upon anyone else except the collector it was addressed to. So, Asset Acceptance is not bound by the DV.
To the OP--is the law firm you sent the DV letter to the same as the one representing Asset in the case against your daughter? Let us know.