Here are three easy ways to say that idea for a 7-year-old:
When I look out the window, spring, summer, autumn and winter each make the outside look different. People, animals and birds do different things and find new ways to enjoy the weather.
From my window the world changes with spring, summer, autumn and winter. People, animals and birds change what they do and discover new fun in every kind of weather.
Outside the window, every season — spring, summer, autumn and winter — looks new. No matter the weather, people, animals and birds try different activities and enjoy new things.
How I changed the sentence (simple steps):
Kept the main idea: the view changes with the seasons.
Used short, clear words so a 7-year-old can understand (for example, "look out the window" and "find new ways to enjoy").
Kept people, animals and birds together and showed they change actions to enjoy different weather.