Are you making the "21 Days of Fasting & Prayer" a family time? If you haven't considered it before, maybe you should, because you can experience God in a dynamic way, when you make the 21 Days of Fasting & Prayer a time to seek the Lord as a family.
When we were children, a 10-year-old friend asked his mother if they include the family pet in the church fast? To his chagrine, he was informed that pets are exempt from fasting. Although pets are excluded from fasting & prayer, it is a good idea to include all the members of our family, as we seek the Lord.
Family fasting - While we certainly can't expect small children to fast for extended periods of time, we can introduce them to the concept of fasting, by sharing biblical truths about fasting with them, and teaching them how God responds when they fast.
Reminder: Children have a much greater capacity for seeking & serving the Lord, than many adults give them credit. That helps explain why Jesus said, "You must become as a little child to inherit the Kingdom of God." So parents - don't underestimate how powerful, and life-changing this time of fasting and prayer can be for your family.
What type of fast can children do? Excellent fasts for kids include the 'Partial Fast' or 'Media Fast.' The Partial Fast is a good choice, because it doesn't require them to skip whole meals (which we don't recommend for children). They can, however, be given them the option of picking a favorite food to fast (abstain from) for a certain period of time. Depending on the age of your children, they certainly don't need to surrender their favorite food for all 21 days, but even a day or two is a good start for young kids. Maybe they could even repeat that fast one day each week, for three weeks.
The Media Fast is a other good choice for kids, because most kids (according to polls) spend too much time on video, computers or watching TV anyway. So you might get a more productive 'sacrifice' of their time, if you push for a Media Fast than anything else. In the end, what we fast isn't as important, as our heart-attitude in it. Remember, the Lord will always honor our best sacrifice.
What food should kids fast? Broccoli probably doesn't count as a legitimately 'sacrificed' food (lol), b but foods like chocolate, or sugary cereal might be good picks for kids. But once again, let your kids help make the choice. You just might be surprised what they will give up, to seek the Lord.
Family prayer - we also encourage you to take time to pray together as a family. Once again, the length of time will vary, depending on the age of your children, but even if you get together and pray for 5-10 minutes each day, you are teaching your family to set aside time to communicate with the Lord. Try this at home: Let each of your children pray for a need each day. You'll be amazed what you can learn by listening to your children pray.
During this time of fasting, another good teaching we need to share with our family, comes from Isaiah 58:6-12. In 'the chosen fast,' the Lord includes, 'Is it not to share your food with the hungry, and to provide the poor wanderer with shelter—when you see the naked, to clothe them.' Take this opportunity to teach them the heart & will of God, by doing good by others.
May the Lord bless you, as you seek His face together!