1.

“Suddenly, she froze. There was something coming up the street on the opposite side. It was something black … Something tall and black … Something very tall and very black and very thin.”

The BFG by Roald Dahl

Roald Dahl could have simply revealed what ‘she’ in the story saw straight away, but he chose to reveal only bits and pieces of information to the readers in order to keep them in suspense before the final revelation.

Yes, stretching the tension is an important tip to help your child achieve a climax in his story.

2.

A moment of tension can be stretched out in 4 steps.
a) Action / Non-action
b) Bits of Dialogue
c) Character’s thoughts/ feelings/ inner sensations
d) 5 senses (what the character saw/ heard/ touched etc.)

3.

Bad example: Amy fell off the ladder

Good example: Amy felt the ladder wobble. “Aargh!” she screamed, throwing out her arms. The room became a sudden blur. Fear gripped her. She tried to grab something but her fingers closed on thin air.