I like the idea of the epistolary form for a children's book. You included many aspects of the city's landmarks but I think I like the imagery in your writing the most. You were able to create these fun little moments where I could visualize the future illustrations. Good luck!
This book is just so charming. I like the twist at the end with the country cousins, and the mooing sound is just the sort of joke that a 2-year-old would adore. You managed to cover a wide range of topics without sounding perfunctory or forced. Well done!