Let them join a chess tournament for kids. It will fire more their interest with chess.
How to not scare the kids off of chess?
lots of ways to challenge kids ....time constraints, play them without your queen, let them have 2 queens. works better than letting them win. still a challenge for both players. I play a 94 y/o each week and we enjoy the challenge 60/40 win ...I play without my queen.

lots of ways to challenge kids ....time constraints, play them without your queen, let them have 2 queens. works better than letting them win. still a challenge for both players. I play a 94 y/o each week and we enjoy the challenge 60/40 win ...I play without my queen.
This has worked very well for me. 8) I give them a queen & a bishop and then try to win and they love it. 8)

I never let me kids win & they know it. They know that when they do beat me though it was because they really did beat me. They are all trying to get better right now to beat me . well 3 of my 4 kids are. I can't wait for the day to come when one of them does manages to beat me... I wish I started playing this game when I was younger but sadly I didn't. Same thing is not going to happen to my kids though cause they all got chessbook for Christmas
Some of my kids have a healthy interest in the game.
When I play them OTB, where's the balance between letting them win and actually pushing their minds to improve beyond random play?