I am smaller than my brother.
And brother is taller than father.
But I am prettier than brother.
And father is smarter than brother.
My family is friendly than past.= My family is friendlier than in the past.

It’s clear that you understand how to form and use comparative adjectives. You correctly changed the adjective forms (e.g., pretty → prettier, smart → smarter), which shows you're learning English grammar rules and applying them with confidence. That’s a big step forward in your writing and speaking ability! Well done~