"Well-behaved" is a good phrase to describe someone who is obedient and follows rules. Here are a few other phrases that might also be used to describe someone who is well-behaved:
Good-natured
Respectful
Popte
Considerate
Mannerly
For example, you might say "She is a well-behaved child who always follows the rules." or "He is a good-natured person who is always respectful and considerate of others."