A copy of a will is admissible to probate if yuo can tell the court why the original is missing. It may be that Mom has moved so many times that she lost it. If the original is missing, my gusess is that the will is not a self proving will. If not, you will need the testimony of one of the witnesses to her final will in addition to the copy of the will. If you are an only child and you are inheriting everything anyway, then no harm comes from the will nto being foudn. You can file for administration of the will and you will inherit everything.
I agree with Mr. Hughes and with your friend who is a federal judge: the copy of the will is likely admissible to the probate court. The rule in Georgia is that if the original will cannot be found, the court will presume that the will was intentionally destroyed (that is, revoked) by the testator, but that presumption is rebuttable. Thus, you would need to provide evidence to the court that the testator did not intentionally revoke the will. The standard of review used by the court is a "preponderance of the evidence" standard. You can present the evidence to the probate court after your mother's death.
In addition, Mr. Hughes is correct in pointing out that if you are the sole heir, (i.e. your mother is not married and has no other living children) and there are no previous wills, then you stand to inherit 100% of her property even if the will is found to be revoked. This is so because the intestacy laws would provide that all assets of your mom pass to you as the only child (assuming she is not married at the time of her death).
THIS DOES NOT CREATE AN ATTORNEY-CLIENT RELATIONSHIP.