WA State: Can heirs dispute a claim leveled against the Estate, if it's the Personal Representative who is claiming it?

The Personal Rep of our father's estate recently procured altered documents (we've had them examined by expert witness/forensic specialist) of shares from our father's company, claiming 50% of his assets. Since she sold all his assets days before his death, in the company's name, the liquidated business assets ARE his estate. I've written about this in a prior post. We wonder now, as heirs, can we dispute this claim, so the court retrieves the proceeds she's collected (RCW 11.76.190) to keep them safe until we untangle everything? And if so, can anyone tell us what form we'd file? I appreciate your advise and time!