Trying to write from a more blunt approach, hope it works. This is based (vaguely) off of some experiences as a kid.
She never likes going to the beach. Even in her short five years of life, she has gathered enough information to determine her opinion on them. And it is a very negative opinion.
Her parents are laughing, joyful as they dance in the ocean. She doesn't join them. She wraps her arms around her legs, sitting on a thick towel shaded by a large umbrella. She wears a scowl on her face.
"Why do you look so down?"
She looks up. A boy, at most a few years older, is standing next to her towel.
"Are you not having fun? Do you like it here?" His annoying questions sour her mood further.
She stands up so she can properly glare at him. "It's stupid. I hate the beach," she says.
"Why?" he asks, seemingly unperturbed by her rudeness.
Her foot shoots out, kicking up a cloud of dust. "I don't like sand. It's ugly and it hurts my feet."
The boy frowns. "Ugly?" His voice is surprised. He reaches for her arm, gently gripping her wrist. "Follow me. I'll show you something really pretty."
Her anger dissipates instantly, and she follows, because oh does she love pretty things.
They walk. His hand slips from her wrist to her hand. She doesn't notice. She's too busy thinking of what the other boy might show her. Maybe something purple, because purple is the prettiest color. They walk past the other people on the beach, until the chatter lingering behind them fades into silence.
He eventually stops, kneeling down next to a small pond. She kneels beside him, but is disappointed.
"Is this it?" She doesn't put any effort into hiding her dissatisfaction.
The boy smiles, before scooping a handful of the ugly, dusty sand into his palms.
"See this sand?"
She does. It's still ugly.
He extends his arms over the pond, and lets the sand spill from his hands.
She is amazed. The moment the sand breaks the water's surface, it billows into a glittering cloud, each speck of sand sparkling radiantly in the sunshine. The cloud remains for several seconds, before the residue falls to the bottom of the lake.
"How did you do that? Tell me!" she demands.
He laughs, but it is not mocking. "You can do it too," he tells her, and she listens with rapture. "Try it: take some sand and drop it in the water."
She grabs a small mound of the not-so-ugly sand, and lets it fall from her hands just as the other boy had. The sand sparkled and glistened just like his had! She grins joyfully.
"Mama says that it's just the light," the boy says, "but I don't think that's true. I think that sand is really stardust."
She is mystified. "Stardust?" she asks in awe. Stardust sounds pretty! It looks pretty too!
He nods. "Stardust. It hides its true form from people, so they don't take it away to somewhere else. You can only see what it really looks like if it's in the water. That's why you find stardust on beaches: because it's close to the water. That's why I love it here… it's such a magical place."
She agrees: she's never realized how magical the beach really is.
Maybe the beach isn't that bad, after all.