From your high hole in the castle's keep, you observe the girl building its outer walls. She sweeps sand upwards, pounding its surface flat with slaps from her hands. You watch grains of sand, each bigger than your fist, flying from the immense impacts, and gape at her strength.
When she's satisfied, she claps her hands, the thunderclap scattering yet more sand. Then she rises, her powerful form throwing you into shadow, your vantage point no more than halfway up her shin. Her hands sit on her hips for a moment as she surveys her handiwork, before she moves to work on the other side.
Rather than step over the walls - one small step for such a giant - she propels herself into the air with a leap, more boulders raining down in her wake.
From your position you're now unable to see her, so you venture outwards and pull yourself to the top of this sandcastle up the rough surface of sand. You can see her sitting once more, and are astonished that you felt no shockwave from the gigantic creature's landing. How was she able to land so quietly, when she's so massive -
You catch yourself, gulping as you once again force yourself to come to terms with the dichotomy of your situation. The girl seems immense, a giantess of myth, but the truth is she's just a little child, and you are one quarter of an inch tall. The world will react to her as normal, regardless of what your senses tell you should be happening. If you can't come to terms with that, you'll never succeed at this tiny survival.
"Bye! Bye!" she suddenly shouts, raising an arm to wave farewell. For a moment you panic, thinking she's talking to you, but you realise she's looking far above and beyond your pathetic self. Turning, you see the boy, some way distant, waving back. He's walking away with the blonde woman.
"Luke's off with his mother," a new voice announces from above, "but don't worry, I'm back now!"
This newest darkness is cast by a grown woman, early thirties maybe, long dark hair hanging loose above her beach-wear. She sinks to her knees before the castle's fortifications, which look even more pathetic compared to the solidity of her legs.
"Building a castle?" she continues, rubbing her hands together. "Cool! What do you need me to do?"
So, the girl's mother is to join in the build. How does that change things? You could still stay and watch, hide and make use of the castle, or perhaps something more?