WHy is my icloud account showing up on a device which I no longer use and is being used by another icloud account holder?

Hi,

I recently gave my old iphone 7 to my wife when I got a new iphone xmax. She has since been using it, updating stuff on the app store, logged in with her own Icloud account. However when it comes to updating certain apps like gmail, google calendar and even netflix, it does not allow her. Instead, it shows my old icloud account and asks her for that password. Why is that happening and how can I fix it so that it asks for her icloud account password?