The main differences between the "Starter set: pen and picture book My World" for 2-3 years and the set with the "Farm Book" for 4-7 years lie in several key areas:

- Content and Complexity:
- The "My World" book is designed for younger children, focusing on basic learning concepts such as shapes, colors, and simple objects. It is more straightforward and easy to follow.
- The "Farm Book" is tailored for older children, introducing more complex themes, stories, and interactive elements that require a higher level of understanding and engagement.

- Interactive Features:
- The "My World" book typically includes simpler interactive features and games that are easy for 2-3 year olds to understand and navigate.
- The "Farm Book" includes more advanced interactive features, such as more intricate stories, puzzles, and educational games that are suitable for children aged 4-7.

- Learning Objectives:
- The "My World" set aims to introduce basic learning concepts and stimulate early childhood development.
- The "Farm Book" set is designed to enhance language skills, problem-solving abilities, and cognitive development in older children.

- Age Appropriateness:
- While your 2-year-old daughter may enjoy the farm theme, the content and complexity of the "Farm Book" are generally more suited to children who are a bit older and have developed more advanced cognitive and language skills.

Given the age gap, the "Farm Book" is not just more difficult but also more comprehensive and aligned with the educational needs of older children. However, if your daughter is particularly advanced or shows a strong interest in the farm theme, you could consider consulting with a child development expert or educator for a more personalized recommendation.