Med Error

I work at a group home for individuals with intellectual disabilities. I am a newer nurse and was left alone in a region for a while and just now got help to manage the group homes and staff.

I recently discovered on the 19th one of the staff members have been passing medications on an expired license that expired the 3rd. All staff members in the group homes who are unlicensed have to get a med card and they pass meds under my license. This staff member never told me it expired the 3rd and continued to pass meds on an expired license until I got an email from the state the 19th. I now have to do med errors for every single date, every med, and every person she has passed medications for from the 4th to the 19th. 

I am unsure if anyone has any experience with this or will know how it will affect my license?