My daughters hair is the same way and we started using the Renewing + attain oil of Morocco penetration oil for all hair types. It can be used on damp and dry hair and it has been really helpful with managing her frizz.
There are a couple of products from R + Co that are great for waves minus frizz. Rockaway - is kind of a "salt spray" it gives you beautiful messy waves. Or the Sail which is similar but is a little more shiny and softer waves. Both smell great!