2 swimsuits
4 sundresses (a strapless one can be used as a cover-up, too)
1 pair of shorts
1 pair of jeans or capris (whichever would be more useful)
2 tops (t-shirts if your dresses can work for dinner out, nicer if you want to wear pants out)
I am assuming in this that it is 10 items PLUS 2-3 pairs of shoes, and for the shoes I'd go with one pair of heels, flip-flops for the beach, and flat sandals for days out.