Donut Baby, known as Donutping, belongs to the Royal Dessert Teeniepings in Teenieping Village. Initially jealous of the attention Cupping and Muffping received from the others, she felt overshadowed by their popularity. This resentment surfaced when she reacted negatively to Heartsping's praise of her drawing, discarding it despite the encouragement.

Assigned to babysit Cupping and Muffping, Donutping accepted the duty reluctantly. Her caregiving faced significant challenges, including managing the babies' chaotic escape from their stroller at a juice shop, where they caused disruptions and rejected one-star milk, demanding five-star milk instead. Exhaustion followed these efforts, yet she persisted. During outdoor supervision, she used humor—making funny faces and playing with her donuts—to soothe Cupping and Muffping after minor mishaps. Gradually, she developed a fondness for them despite their mischievous actions, like throwing dirt at her.

A critical moment arose when a crow threatened the babies. Paralyzed by fear at first, Donutping then recalled her positive experiences with Cupping and Muffping, galvanizing her courage. She intervened, using her ability to throw donuts as weapons against the bird. The confrontation escalated into a physical battle, culminating in Donutping delivering a decisive punch that drove the crow away. This act solidified her protective role and emotional bond with the infants.

Throughout this journey, Donutping evolved from a resentful observer to a dedicated guardian, embracing an "older sister" dynamic with Cupping and Muffping. Her initial reluctance transformed into genuine care, underscored by her willingness to prioritize their safety over her own comfort.