If you haven’t or can’t prove that you are a citizen, you’re not going to get a clearance. Does your mother not have the information or does she just refuse to give it to you?
A passport will not suffice as proof of citizenship. What documentation did you use to get your passport?
There are rare case where people do not have naturalization certificates or a certificate of citizenship. In this case I have advised subjects to contact USCIS to get a new one( this is costly and can take time) or if one does not exist, explain it the best way possible.