In mainstream parish Masses, it is recommended that the priest should address children present. I’ve only ever known one priest who did this consistently:
17. Nevertheless, in Masses of this kind it is necessary to take great care that the children present do not feel neglected because of their inability to participate or to understand what happens and what is proclaimed in the celebration. Some account should be taken of their presence: for example, by speaking to them directly in the introductory comments (as at the beginning and the end of Mass) and at some point in the homily.
My parish does celebrate a children’s liturgy of the word. Here it is suggested:
Sometimes, moreover, if the place itself and the nature of the community permit, it will be appropriate to celebrate the liturgy of the word, including a homily, with the children in a separate, but not too distant, room. Then, before the eucharistic liturgy begins, the children are led to the place where the adults have meanwhile celebrated their own liturgy of the word.