This fabric is Chez Ami swimsuit lycra, which I absolutely love. (I have coordinating board short fabric and matching green terry that I plan to make cover up pieces for the girls with as well, but that's a post for a different day.)
It is a tankini, which is my preference for the girls. . . they make bathroom breaks 100 times easier! I attached the straps near the center back to keep them from slipping off her shoulders.
I used my usual Kwik Sew bikini bottom pattern because it provides the coverage I think they need. The top started with the Seahorse one-piece pattern from Ottobre. I tried a new technique for the straps. I've done bound edges on suits before, but I've never put elastic in the binding, and it has always seemed pretty flimsy. I used the tutorial here and absolutely love the results.
And even though we haven't brushed hair or washed faces yet this morning, this picture is too cute not to show. She has informed me that she is going to surf when we go to the beach.