Meaning: The stranger was glad to have helped the boy.
Choice of Words:Happily means that the stranger was pleased.
Alternative Expressions
The stranger beamed with joy.
Meaning: This means that the stranger was very happy and showed it by smiling very widely.
Choice of Words:Beamed means to smile broadly, especially with happiness or delight. Joy means a feeling of great pleasure or happiness. When you put them together, "The stranger beamed with joy" means that the stranger smiled very widely because they were very happy.
The stranger's face lit up with a smile.
Meaning: This means that the stranger's face became bright and happy when they smiled.
Choice of Words:Lit up means to become bright or illuminated. Face is the front part of your head where your eyes, nose, and mouth are. Smile means to show happiness by turning up the corners of your mouth. When you put them together, "The stranger's face lit up with a smile" means that the stranger's face became bright and happy because they smiled.