Final answer:
Three-year-old Natalie is likely to feel happy that her cracker is still in one piece.
Step-by-step explanation:
Three-year-old Natalie is likely to respond to the situation by feeling happy that her cracker is still in one piece. At this age, children often have difficulty understanding other people's points of view and may be focused on their own immediate desires and preferences. Natalie may not yet have the cognitive ability to understand why her sister's cracker is split into two pieces or to want her own cracker to be split.