mikesimon has given you excellent advice. I would just add one thing and that is if it was the doctor that said her hepc was " dormant and just showed up now" she should possibly be advised to be seen by another physician ,as he may be very limited in his knowlwedge of treatment for such.
Hep C doesn't go dormant - it is always active. But that doesn't mean it's necessarily doing significant damage. Many factor play into the course of the virus. There are host factors, coexisting diseases, viral genotype and lifestyle choices. So maybe your Mother never got tested and never felt ill from the disease. Many people never know they have HCV until they undergo a blood test. Hep C isn't an easy virus to contract. It is generally through blood to blood contact. There is some incidence of vertical transmission - from Mother to Baby(probably somewhere around 5%).
So, it's possible you do have the disease but I would doubt it. Get an antibody test and go from there if you're worried. I probably would.