What sort of “alternative” do you have in mind?
Children under 14 aren’t bound to the rule of abstinence from meat, but children usually eat what the rest of the family eats, so if the family is having macaroni and cheese on a Lenten Friday I assume that’s what the children eat as well. And there’s not a lot of difference in taking a tuna sandwich to school rather than baloney.
As far as observing Lent through prayer, fasting, and almsgiving, children can do those things at their level just as adults do it at their level. They can join in family prayers or perhaps make a Lenten promise to be especially kind to their siblings as a way of preparing for Easter.
