My Mother Was Given Zovirax To Treat Shingles. The Dosage

My Mother was given Zovirax to treat shingles. The dosage was 800 mg 5 times a day for 7 days. Today is her 8th day since the diagnosis and she has taken all the medication. She still has blisters and may be getting a few more. She did let this go for too long before seeking medical treatment. Can she be prescribed more antiviral or does she just need to wait it out?