Whether you have just 2 kids in your church or 20 or 80 who are regularly there you need to think about how to include them in your church family - both in services which they stay in for but also if they’re going out to a Sunday School or a creche.
The Gospel Coalition recently published this article: 25 Tiny Ways to Welcome Kids in Church which contains very helpful ideas for the adults in the congregation to know, love, serve and engage the kids. There’s only one idea here I disagree with: under love it suggests you carry a treat - but unless you know the allergies of and have parental permission for every child and are prepared to find every kid and give them all a treat I do not recommend this as a good tactic.
Since you’re likely to have kids in services over Christmas and you’ve got a chance to rethink how yo do things for the next year, check out my favourite ways to get children an young people involved in the life of the church.