Five kid-friendly rewrites of the question
What can show up on your face because you spent time in the sun, like tiny brown dots called freckles?
Why might you see little brown spots on your face after sunny days?
What tiny marks on the face can appear when the skin is in the sun, often called freckles?
What name do we give to small brown dots that can appear on the face from sun exposure?
How do freckles show up on the face after being out in the sun?