Yes many years ago my sister took $240,000 from my father's bank account because he spoke to a notary and realized he was leaving her nothing.

You face perhaps insuperable challenges.  First, you must prove that your father intended to leave the money to you, perhaps in a Will.  Second, you must prove that your sister defrauded your father.  Third, you must find your sister.  Fourth, you must find the money  Fifth, the statute of limitations may have run:  it may be too late.