This coming Sunday (14 February 2021) is the last Sunday we use “Alleluia”. “Alleluia” is not used during Lent which begins the following Wednesday (17 February 2021). It will next be heard at the Easter Vigil.
A children’s activity could involve Burying the Alleluia. You can be creative about this. Maybe there is a banner (or banners, or even an altar cloth) with “Alleluia” on it. This could be put into a box and stored, or even buried. Obviously children can participate enthusiastically in this.
Or children could be encouraged to produce their own “Alleluia” artwork – this could be collected and they, again, could put them into a box for storage or burying.
On Easter Eve, the box can be dug up or taken out of storage and the Alleluias can be displayed as part of the Easter Season celebration.
A children’s talk can explain the significance and meaning of “Alleluia” (some adults may not know either!) and how responses in the Easter Season have “Alleluia” added to them.
All this is just as possible to do as an activity at home – as well, if you like, [depending on your local Covid restrictions].