Amazon RDS for SQL Server Now Supports Native Backup/Restore on DB Instances with Read Replicas
Amazon RDS for SQL Server now supports restoring SQL Server native backups onto DB instances that have read replicas configured. Previously, the read replica would need to be removed before restoring the native backup file onto your Amazon RDS for SQL Server DB instance. SQL Server backup files stored in your Amazon S3 bucket can now be restored directly on DB instances with read replicas.
Source:: Amazon AWS