The T5_Inserts feature class from the delta geodatabase will contain whatever changes were made to the parent geodatabase since the last sychronization and acknowledgement transpired between the parent and child (replica). Modifying the feature class in the delta geodatabase will probably lead to a plethora of problems with respect to applying the changes to the child correctly and to keeping the two geodatabases in sync as a whole. I would not recommend editing the delta geodatabase. If you want to fix this issue, I would suggest going back to the source feature classes within the parent and fixing the data at its origin. You mentioned that features were accidentally copied into another feature class. It should therefore be possible to start an edit session on the parent geodatabase and copy the features back to the appropriate feature class (or delete them entirely depending on what you had intended). From there, you would generate another delta geodatabase, import it to the child, and then acknowledge it. In other words, get the data issues fixed on the parent and then proceed with the synchronization process.