Finding products that are waterproof? Easy. Finding products that are solar-powered? Not so easy. Finding products that are both waterproof and solar-powered? Practically impossible!
If you live by the beach throughout the Summer (a pool works too!), then may I suggest checking out this Tocs Ani-Digi Solar Chronograph Watch? It stays juiced up from the sun (with a lithium battery for backup) and is water resistant up to three meters deep.
Now I know it doesn't scream cute, feminine watch (I'm hoping it's unisex), but it does come in orange or black as well. And best of all, it's only $50.