The first four articles of this series are available in the Learning with Fun group forum.
A well-known chess recipe to fight against a gambit is to take the pawn on offer, and give it back sometimes later to complete development. The key idea here is not to give back the pawn, but to complete development : that's the development advantage that gives the ability to the attacker to overcome the defences by outnumbering the defenders.
So if your opponent offers you a second pawn, be careful that taking it doesn't let you fall too far behind in development.
Here is a case in point :