No, you do not owe it personally: it was her bill, not yours. Her "estate" does owe it, which means that it should be paid from any money, etc. she had left at the end (after paying her final expenses), but if there is no money, the credit card company is out of luck. The liefe insurance is not vulnerable if it was left to you and your brother by name, since in that case, it goes to you directly, *outside* the estate and is never part of her funds.