How do I find where all my mothers money and Will went?

If you know that your presumed deceased mother had a Will, you need to ask your sister as to its wherabouts. If your sister was on a joint account with your mother, there is a good chance that the acount was a joint tenancy account. If so, your sister as a matter of law would be entitled to the full account upon your mother's death.

If you do not get the answers you want from your sister, you should then consult with a Wills and trust attorney about the current situation and the best way for you to proceed in order to obtain the answers that you need.