She sold more than 10 million records after becoming an opera star aged 11, and the money she earned went into a trust fund to keep it safe.
She denied rumours that she's buying a house in the Caribbean, and plans to celebrate with friends and family.
She said she didn't care about cash: "I don't need a lot of money now."
Charlotte had an early celebration when children at a hospital she visited on Thursday presented her with a cake.
She is part of the Noah's Ark Appeal, which is trying to fund the first children's hospital in Wales.
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Charlotte Church: When I was 12
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