She is Sally Brown.
Sally Brown is Charie Brown's little sister. She doesn't have a clear understanding of the world, and is gullible enough to stay out all night with Linus waiting for the arrival of The Great Pumpkin.
She frequently writes letters which showcase her incomplete understanding of the world, and yes, she is a blonde. She has a Romantic crush on Linus VanPelt and frequently calls him My Sweet Baboo.
Did you know: For 6 months, Sally experienced amblyopia ("lazy eye") and wore an eye patch.
Learn more about the famous comic strip and its creator at History.com.