Create a Wishing Jar
Get a jar with a lid, which can be decorated by your child. Let your child write each of his/her wishes on a separate small paper. Roll each paper up individually and put an elastic band around it. Let your child do a prayer in his/her own way to ask within herself for the wish to be fulfilled, then put it inside the jar.
It is also possible to create a wishlist instead of many small wish papers.
Check every birthday or new years day which wishes have or haven't come true. Let your child give thanks within him/herself for fulfilling the wishes which came true. This is also a good moment to add new wishes.
Remember that wishes are unlimited, accept and be open to whatever wish your child has.