Question

Ashwin mother is able to swim in a forward direction only when he is pushing the water in the backward direction

Answer 1

But ,what is your question? And you have to use she because Ashwin's mother is female.

Answer 2

Newton's III law is applied to understand the following process
+ Every action have equal and opposite reaction .
"Because when swimmer push the water in backward direction which is action force , water also exerts equal and opposite force on swimmer that is reaction force . So the swimmer can able to swim ."