How many years from the origination of a debt can a debt collector file a law suit in Maryland? Do the clock start over every time the debt is sold?

My daughter has an old CC debt from 2003. The bank no longer has any record of this debt, but it shows up on her credit report. She doesn’t remember having a CC with this bank. We have been getting collection calls from a shaky collection agency in CA, claiming they have bought the debt and that they will garnish her wages to the tune of $1000 a month. They claim the balance is $16,000 but the credit report says $12,000. We are skeptical as to the validity of this claim.