I think Adalyn goes best! Easton and Rowdy are so uncommon, you need a somewhat uncommon name to go with them, not a supper common one like Charlotte. Although, I also love Summer and think it works too! I disagree with the poster above, if you go with Mackenzie, I like your spelling, not the capital K spelling. Also, having a common M last name, I wouldn't use a first name that starts with M, or a super common fn like Charlotte. Callie is ok, but feels incomplete to me. Easton, Rowdy, and Adalyn! They sound great! And Addie is an adorably nickname!