CBCPA

Daughter inherited mother's Roth account 18 years ago and was not informed about RMD requirement, so no distributions taken. Mother over 59 1/2 but had not held account for 5 years at death. No options for daughter now except draining account? Since daughter has held account for 5 years, are earnings taxable? What would penalty for lack of RMDs be based on - just the earnings?