Your child should be able to read and spell all of the kindergarten and first grade words by the end of first grade. If you would like to challenge him/her and they have mastered all of the above mentioned words, move on to the second grade list!
https://docs.google.com/document/d/1vNZErer7WUHQijHY7WcRbCUqoEU6flsMZs4rKpYz5xA/pub